Jewish Influence on American Politics

In this post, I will argue that Jewish people have become highly represented among circles of American elites, that this has shifted the political ideology of American elites towards leftism and Zionism, and that the leftist and Zionist ideology of Jewish elites is partially explained by ethnocentrism on the part of Jews. This should go without saying, but nothing in this post should be taken as an attempt to justify mistreating anyone simply because they are Jewish. Anyway, in the United States the socioeconomic status of Jews was basically the same as that of English, Scottish, and Irish, Americans in 1910, but was considerably higher by 1980 .

(Lynn, 2011)

Similarly, in the 1940s Jews were 20% less likely than gentiles to be included in America’s “Who’s Who”. By the 1990s this disparity had reversed such that Jews were 4.7 times more likely than non-Jews to be included in the list.

(Lynn, 2011)

Using a more fine grained analysis, it can be seen that this shift represented an increase in Jewish and Catholic dominance and the fall of the liberal Protestants who represented 53% of America’s intellectual elites in 1930 but only 27% in 1976.

Davidson (1994)

Elsewhere, I’ve written about the political influence of Catholics. This influence was substantial in large part because Catholics had power as a humongous voting block. By contrast, Jews are only around 2% of the US population and so have never been an especially important voting group. But as we’ve already seen, Jews do make up a significant proportion of America’s most influential individuals. This becomes more true the more elite the sample under consideration is. This can be seen in data from the 1960s showing that Catholic and Jewish academics were more common in elite universities and especially among young professors at such universities.

(Lipset and Ladd, 1971)

This data suggests that the majority of young elite leftist academics, the ones who would dominate the left in the coming decades, were not protestant. This is notable given that the vast majority of Americans at that time were protestant. Similarly, Zuckerman (1977) found that Jews were over-represented among university faculty by a factor of three when looking at a general sample of American schools but were over-represented by a factor of seven among faculty at America’s most elite universities. In some fields, Jews were over-represented by factors as high as 13: Kadushin (1974) analyzed the authors who were recently published in the top 20 academic journals in America and found that Jews accounted for 50% of intellectuals, 56% of social scientists and 61% of humanity scholars , corresponding to factors of over-representation of 18.5, 20.7, and 22.6. Turning away from academia, page 309 of Lynn (2011) reports on 5 analyses of Jewish representation among media elites in contemporary America: The figure in the first row is taken from an analysis by W. D. Rubenstein published on page 61 of his 1982 book The Left, The Right, and the Jews. Rows 2 – 4 report the results of 3 analyses published in Forbes. The first defined elites as those who worked in the news divisions of the three largest tv networks and PBS, the three largest news magazines, and the four biggest newspapers. In row 3, the criterion is directors and producers of Hollywood TV shows and in the 4th-row the criterion used is directors and producers of Hollywood movies. Row 5 is an analysis of a vanity fair article that listed the 23 most important media people in America. The mean factor of over-representation across the table is 19. Turning from those employed in the media to those who run the media, a 1990 list of the top 10 US entertainment companies published in American Film found that Jews accounted of 8 of their ten CEOs (Lynn, 2011). The companies were Time Warner, Paramount, CBS, Fox, Columbia Pictures, Viacom, ABC, and MCA Inc. More recently, in 2012 Business Insider reported that six companies controlled 90% of American media: News-Corp, Disney, GE, Viacom, Time Warner, and CBS (Lutz, 2012). Of these, three had Jewish CEOs at the time the list was made: Philippe Dauman (Viacom) Bib Iger  (Disney) and Leslie Moonves  (CBS). Finally, it’s worth noting that five of nine current supreme court justices are Catholics, one was raised catholic, and the other three are Jewish.

Thus, by the late 20th century Jews were common enough among America’s elite to significantly alter elite ideology.

Political Influence

Given the general voting patterns of American Jews, it would be surprising if Jews didn’t push American elites to the left.

(Weisberg 2012, Stone 2012, Smith and Martinez 2016)

And this is exactly what the data gathered in 1969 on 60,000 American academics suggests. This survey is reported on in Lipset and Ladd (1971). As can be seen,Jewish academics were to the left of gentile academics. This data implies the following representation of Catholics, Jews, and Protestants, among academics of each political orientation (excluding atheists):  Three things are worth noting. First, Jewish Americans, who are only 2% of the population, were greatly over-represented among left wing academics in a way that they were not over-represented among right wing academics. Second, Jews did not comprise the majority of leftist academics but they clearly shifted the distribution of academic opinion leftward. The best data on this is provided by Lerner et al. (1989) who somehow managed to administer political surveys to a random sample of over 1,300  high status members of the military, the media, law firms, the government, etc, and then reported on the difference in opinion between gentile and Jewish elites. What they found is that gentile American elites had a slight right-wing bias but the addition of Jewish American elites pushed the mean opinion in the other direction creating a significant bias in favor of the left.

 Lerner, Nagai, and Rothman (1989)

Similarly, surveys given to physical anthropologists in the 1970s found that Jewish anthropologists largely disbelieved in race as a biologically valid concept (a distinctly left-wing view) while the opposite was true of gentile anthropologists.

Lieberman and Reynolds (1978)

(This result is based on a small sample of Jewish anthropologists, but is statistically significant.) This is consistent with the impression one gets from looking at the “Sociobiology Study Group”, an important organization of scientists who opposed biological explanations of human psychology in the 1970s. Wikipedia lists 7 members/associates of the groups which were important enough to have their own wikipedia pages. Of these, 6 (Lewontin, Gould, Beckwith, Hubbard, Chomsky, and Keller)  or 86% are also identified by Wikipedia as being Jewish (Wiki, 2020).

Similarly, the PBS documentary “From Swastika to Jim Crow” reported that “About 50 percent of the civil rights attorneys in the South during the 1960s were Jews, as were over 50 percent of the Whites who went to Mississippi in 1964 to challenge Jim Crow Laws – (PBS, 2000)”.

Of course, these data sets are decades old and may not reflect the current reality. Once leftists took over various institutions a selection process began such that today gentiles who gain power in the media or academia are probably more likely to be leftist than they would have been in the past. But this filtering out of conservative voices was only possible because of the initial capture of American institutions by the left and this process was a direct result of the inflow of Jews into the American elite. More recently, data published by the mainstream Jewish magazine The Forward on Americas top 50 political donors shows that a super-majority of mega-donors in the democrat party are Jewish while most republican mega-donors are gentiles.

Troy (2016)

An exception to the general pattern of Jewish elites being to the left of gentile elites concerns Zionism. Lerner et al. (1989) found that the statement “The United States has a moral obligation to prevent the destruction of Israel” was more likely to be believed by Jewish elites (88%) than gentile elites (60%). Of course, in a way the influence that Israel has on America necessarily represents a particular manifestation of Jewish influence the country and Israeli influence has not been uncontroversial. Common complains concerning the US-Israel relationship include the following:

• In 1954 Israel attempted to bomb US assets in Egypt and blame it on Muslims in order to manipulate our foreign policy and held a ceremony honoring those who had participated in the so called Lavon affair as recently as 2005.
• The US has given Israel over 230 billion dollars in aid (Coren and Feldman, 2013).
• Groups like AIPAC and the ADL play a significant role in current American politics despite the fact that both organizations have been investigated for spying on the US for Israel (Leferbvre, 2006; Ames, 2014).
• As of 2019, 26 US states have passed laws which punish companies that boycott Israel, an obvious violation of the first amendment (Beauchamp 2019).

There is also evidence that Israel played a large role in the Bush Administration’s Office of Special Plans, an organization that many today say produced biased or false intelligence that manipulated the US into going to war with Iraq. This organization was led by Paul Wolfowitz and Douglas Feith. This leadership connected the OSP to Israel in several ways:

• In the 1970s Paul Wolfowitz was investigated for spying on the US government on the behalf of Israel (McMahon, 2008; Piper, 2007).
• Douglas Feith worked for the Israeli government in the 1990s authoring papers calling the removal of Saddam Hussein an “important Israeli strategic objective“.
• People working under Wolfowitz and Feith, like Lawrence Franklin, were later convicted of spying on the US for Israel.

Given that it is already widely believed that this group interpreted and/or manufactured evidence in a biased fashion with the intent of leading us into war with Iraq, it seems not at all unreasonable to think that part of this bias may have reflected what Wolfowitz and Feith perceived to be in the interest of Israel. Consider also the following document that that Wikileaks released from Hillary Clinton’s email concerning the US’s motives for intervening in Syria:

“The best way to help Israel deal with Iran’s growing nuclear capability is to help the people of Syria overthrow the regime of Bashar Assad… Iran’s nuclear program and Syria’s civil war may seem unconnected, but they are. For Israeli leaders, the real threat from a nuclear-armed Iran is not the prospect of an insane Iranian leader launching an unprovoked Iranian nuclear attack on Israel that would lead to the annihilation of both countries. What Israeli military leaders really worry about — but cannot talk about — is losing their nuclear monopoly… It is the strategic relationship between Iran and the regime of Bashar Assad in Syria that makes it possible for Iran to undermine Israel’s security — not through a direct attack, which in the thirty years of hostility between Iran and Israel has never occurred, but through its proxies in Lebanon, like Hezbollah, that are sustained, armed and trained by Iran via Syria. The end of the Assad regime would end this dangerous alliance… Bringing down Assad would not only be a massive boon to Israel’s security, it would also ease Israel’s understandable fear of losing its nuclear monopoly. Then, Israel and the United States might be able to develop a common view of when the Iranian program is so dangerous that military action could be warranted.”

Other releases from Wikileaks have revealed that the US was funding anti-Assad propaganda campaigns as early as 2006 (Zirulnick, 2011).  It wasn’t until 2011 that the Syrian civil war began, and by 2012 the war was settling down. Peace negations were being discussed and there was a cease fire. It was around this time that the US began secretly giving weapons, training, and money, to Islamist groups in Syria, several of which had been allowed to grow in the first place due to the US pull out of Iraq after we got rid of Saddam. Shortly there after, the war erupted into the blood bath that caused the refugee crisis. Meanwhile, the US would continue its process of selling weapons to people that would ultimately get them into the hands of ISIS members throughout Syria (Micheals, 2017). Again, it does not seem at all unreasonable to suggest that Israeli interests played at least a partial role in motivating US intervention. Hopefully, these examples have communicated the problematic nature of Israeli influence on US politics. Some feel that American elites have become less pro-Israel in recent years. This may be so, but this does not contradict the view that Jewish elites made us more pro-Israel than we otherwise would be. And the actions of the US government make it obvious that Israel is still supported by those in power in the ways that matter most. Anyway, the leftist and Zionist influence of Jewish elites may at first glance seem at tension with one another but in fact they can both be explained in terms of what Jewish elites perceive to be in the interest of Jewish people.

Ethnocentrism

Looking at data from the American Jewish Committee’s Annual Survey of American Jewish Opinion (years 1998 – 2003), we can see that American Jews consider the Religious Right to be among the most anti-Semitic groups in the US. Given that the christian right is far more prevalent than Muslims in the US, it would be reasonable then for Jews to oppose the right in an effort to fight antisemitism. This would explain why the AJC’s surveys also show that Jews who describe being Jewish as very important to them identify as Democrats rather than Republicans by larger margins than do Jews who describe being Jewish as fairly important or not very important to them. (AJC binned “fairly important” and “not very important” together. Had they not, I suspect we would see an even stronger difference.) Of course, being worried about antisemitism can lead to a general opposition to nativism if you think that discrimination against other minorities increases the probability of discrimination against Jews. This contention was lent some support by Cohen (2018) who found that the degree to which Jews thought other minorities were being discriminated against positively correlated with the degree to which they were concerned about antisemitism even after controlling for general political ideology, Jewish identity, and the rate of antisemitic incidents in their state. This would also explain why it is that American Jews, but not Israeli Jews, are more likely to say that fighting for equality is an essential part of what it means to be Jewish than they are to say that caring about Israel is.

Lipka (2016)

Similarly, data from ACJ’s surveys shows that when Jews are asked what is the single most important aspect of their Jewish identity they are most likely to say ancestry followed by a commitment to social justice. Contrary to the perceptions of some gentiles, less than one in five Jews say that religion is the most important determinant of their own Jewish identity. The same result has been found by Pew in samples of both American and Israeli Jews.

Lipka (2016)

The AJC’s surveys also contained questions about immigration and in four instances I was able to test whether Jewish identity positively correlated with left-wing views on immigration. In two cases it did (2002 and 2003) and in two cases there was no relationship (2006 and 2007). It’s worth noting that Jews are not always left-leaning. For instance, Pew Polling finds that a mere 8% of Israeli Jews describe themselves as being on the left while 55% describe themselves as centrist and 37% as being on the right. This is radically different from Jewish opinion in any other nation. Of course, the Jews who are in Israel are not the same people as the Jews who are in America. Still, this difference is obviously consistent with the view that American Jews lean left, in part, because it is in their perceived group interest because they are a minority In totality then, the evidence suggests that Jews see egalitarianism as being bound up with Jewish identity and this is most easily explained by the fact that Jews see a relationship between right wing ideology generally speaking and antisemitism. Of course, this process need not be conscious. It could very well be largely intuitive and transmitted via a culture that has helped Jews survive as minorities in various nations for well over a thousand years. On the other hand, a more explicit understanding is suggested by Jones (2012) who reports that “Seven-in-ten Jews cite the immigrant experience in America, and approximately two-thirds say that being a religious minority in America has a somewhat or very important influence on their political beliefs and activity.” Not only does this directly support the contention that Jewish political ideology is defined by what they see as being in the interest of Jews and similar minorities, it also contradicts the view that American Jews simply don’t care about the fact that they are Jewish. The AJC’s surveys offer further evidence against this suggestion. Similarly, Jones (2012) finds that “More than 4-in-10 (42%) American Jews say that being Jewish is either very important or the most important thing in their lives. Approximately 3-in-10 say being Jewish is somewhat important (29%), and approximately 3-in-10 (29%) say being Jewish is either not too important or not at all important in their lives.” And Pew (2013) finds that “More than nine-in-ten Jews (94%) agree they are proud to be Jewish. Three-quarters (75%) say they have a strong sense of belonging to the Jewish people, and about six-in-ten (63%) say they have a special responsibility to care for Jews in need around the world.” Furthermore, studies which compare Jews to other Americans on measures of ethnocentrism (and remember, being Jewish is an ethnicity rather than a religion to most American Jews) consistently find that Jews score above average on such metrics.

Citation	Finding
Guhname (2011)	Jewish participants scored .29 SD above average on a 4 point measure of ethnic identity.
Guhname (2009)	Jews scored .20 SD above average on a measure of racial identity.
Guhname (2010)	Jews were more likely than any other ethnic group, and over twice as likely as whites, to say that marrying within their ethnic group is important (47.4%).
Guhname (2010)	Jews were the least likely of any ethnic group to say they did not prefer the company of their own ethnic group.

Higher than average ethnocentrism is also evidenced by Jewish patterns of marriage. Jewish people make up only 2% of the US population, but most Jewish people are married to fellow Jews. This was true for nearly all of US history, but has recently begun to change: Some have suggested that Jewish marriage patterns no longer suggest any ethnocentrism on the part of Jews because their inter-marriage rate has fallen below 50%. This is confused for two reasons. First, the relevant question is whether Jews marry fellow Jews at a rate that is greater than they would if they were mating randomly. Clearly a population that makes up 2% of the general population is still going out of its way to intermarry if their marriages are still endogamous 42% of the time. The fact that 42% is less than half may have some special psychological significance to us, but it has no logical bearing on whether the value is an indicator of ethnocentrism. This is especially obvious if we consider what we would think if white Americans only married fellow white Americans 52% of the time. This would indicate that white Americans were going out of their way to not marry each-other and would obviously not imply a high degree of ethnocentrism. Again, the relevant comparison is random mating, not 50%. Second, Jewish marriages to gentiles seems to largely be a phenomenon that occurs during second marriages. When examining marriages between 1982 and 1987, a period in which only 59% of Jews were married to fellow Jews, Kosmin et al. (1989) found that American Jews married other Jews 86% of the time for their first marriage and 67% of the time for their second. Similarly, Keysar et al. (1991) found that even among Jews whose first marriage was to a fellow Jew their second marriage only had a 58.4% chance of being to a Jew. Among Jews whose first marriage was not to a jew, this probability was even lower (26.6%). While more contemporary research does not, to my knowledge, exist, this data suggests that Jewish marriage patterns probably look more like traditional Jewish behavior if we look only at first marriages. This fact is relevant to certain evolutionary models of ethnocentrism which frame the purpose of intra-racial marriage as being the production of same race offspring. Obviously, this end can be accomplished in a marriage that later dissolves once people have passed the prime age for having children. Importantly, a limitation of all this data on marriage rates is that it cannot tell the degree to which Jews are marrying their co-ethnics due to ethnocentrism as opposed to traits besides ethnicity that Jews tend to share. This is hard to overcome empirically (and there are conceptual issues with differentiating ethnocenticism and a preference for people who act like the typical member of your group), and so it is important that the direct survey data on ethnocentrism indicates the same thing. The empirical evidence thus indicates that American Jews care a good deal about being Jews and do so to a greater extent than Americans generally care about their ethnicity. And as we’ve already seen, the evidence also suggests that Jewish political ideology is partly a function of what is perceived to be in Jewish interest. some may object to a unified explanation of Zionism and leftism in terms of ethnocentrism by noting that there’s recently been increased pressure in some leftist circles to oppose Israel on the grounds that they are mean to Palestinians. So it may be that there’s been a separation of these views in the past decade or so. I don’t know whether this is true, but if it is this would not contradict both view stemming from Jewish identity. By analogy, some liberal black Americans support affirmative action because they think it will help black people while some conservative black people oppose affirmative action because they think it has hurt black people. In both cases, these views are motivated at least in part by the perceived interests of black people. Upon hearing this, some may fear that this view is unfalsifiable. It may seem that any view a Jewish elite takes can be arbitrarily explained by a story about Jewish interests. This is not so, as the evidence that Zionism and leftism are motivated for Jews by their ethnicity is not merely supported by theory but also, and more importantly, by survey data in which Jews essentially openly say that this is so. Anyway, the statistical evidence is also largely consistent with the notion that Jewish people have materially benefited from Jewish social networks. In part, this is to be expected as minorities usually form communities that give rise to business connections and often try to help each-other out in a preferential way.

Citation	Finding
Berger et al. (2002)	Involvement in the Jewish community correlated at 0.17 with  income.
Hartman et al. (2011)	Involvement with the Jewish community predicted higher levels of labor participation, income, and educational attainment.
Greenwald et al. (1994)	Jewish academics cited fellow Jewish academics about 40% more often than gentile academics did.
Perreault et al. (2012)	Jewish business owners reported that roughly 25% of their employees and customers were Jewish despite Jews being far less than 25% of the local population. However, firm ethnic-nepotism also negatively correlated with firm performance.
Wai et al. (2015)	In an analysis of individuals with a net worth exceeding $30 million, Jews were found to have higher than average “network power” (the net worth of the individual’s known social network)

However, such ethnic nepotism often is of limited value because minorities are generally poorer than average and the poor preferentially networking together can actually bring themselves down economically. But of course Jews have attained a higher level of socio-economic status than average and so there are plausible theoretical reasons for supposing that nepotism may be more beneficial for them that it is for the average minority group. It should also be noted that this statistical evidence is observational in nature and, for obvious reasons, no experimental research is likely to ever be done on this topic.

Counter-Explanations

It’s also worth mentioning, in brief, that some people think a success oriented culture explains Jewish success but, in fact, the evidence on this is all observational in nature and when cultural differences between Jews and gentiles are found they normally are not tested for a correlation with real world success. When they are, they are just as likely to come out negative as positive.

Citation	Finding
Clark (1949)	Jewish students’ GPAs exceeded what would be predicted by scores on an index of aptitude leading the authors to speculate that cultural attitudes and motivation may also play some role.
Rosen (1959)	Jews expected more than gentiles from their children in terms of achievement, independence, and occupational status.
Veroff et al. (1962)	Jews scored above average on a measure of achievement motivation, but said scores were unrelated to income.
Carney et al. (1963)	Jews scored above average on scores of achievement motivation (.31 SD) but said scores were not linearly related to life outcomes.
Kosa (1969)	Jews placed more importance than average on income and prestige.
Fejgin (1995)	Jewish 10th graders spent 1.66 hours more than average on homework weekly and .71 fewer hours watching TV. They also scored higher than average on a measure of academic aspiration. Aspirations predicted academic ability but did not explain the totality of the Jewish advantage in ability.
Lynn and Kanazawa (2007)	When selecting values to instill in their children, Jewish parents placed more value than other parents on judgement, interest, and judgement, and less importance on cleanliness, honesty, manners, and obedience.

Of course, this doesn’t prove that culture has no impact. But it is notable that the evidence here is no stronger, and perhaps is weaker than the evidence for nepotism. Sometimes, it is suggested that the elite status and left wing ideology of Jews can be explained with reference to their IQ scores. It is true that Jews have relatively high IQs. Specifically, Lynn (2011) estimated the mean (Ashkenazi) Jewish IQ to be 110 based on a review of dozens of studies. That being said, there are good reasons to think that IQ cannot be the complete explanation for the elite status or political ideology of Jews and there is no evidence which rises to the level of being so strong that it gives us good reason to doubt the evidence linking ethno-centrism to Jewish political opinion. Based on a mean advantage of ten points, we would expect Jews to be over-represented among those with an IQ of 130 by a factor of 4 and among those with an IQ of over 145 by a factor of 7. This obviously cannot fully explain why Jews account for between one and two thirds of various super-elite groups, with corresponding to factors of over-representation often exceeding 14 and sometimes exceeding 20. Moreover, IQ is something of an anti-explanation for why it is that Jews are overwhelmingly democrats. In the literature there is an empirical debate wherein some claim that republicans simply have higher mean IQ scores than democrats and others add the (empirically disputed) caveat that higher IQ begins to predict a shift to the left once you reach the 85th percentile of IQ (roughly 115) (Carl, 2014; Solon, 2015). Regardless of where we come down on this dispute, the mean Jewish IQ of 110 implies that their IQs should predispose them in favor of being republicans. Granted, high iq republicans tend to be of the libertarian type. Onraet et al. (2015) conducted a meta-analysis finding a -0.20 correlation between cognitive ability and right wing social attitudes. Since Jews have a mean IQ .66 SD above the white mean, this would predict them having social attitudes that are .13 SD more liberal than average. Obviously, this is a weak effect which could theoretically do some work to explain Jewish libertarians but sheds little light on why it is that Jews are generally quite far to the left of the general public on social issues and so vastly over-represented in circles of elite leftists. Sometimes Jewish success and leftism are said to be the result of educational attainment and living in a large city. This view was tested by Mazur (2007) who compared a large sample of Jews to a set of “controls” who were White, college educated, and lived in one of the nation’s 100 largest cities. These controls self-identified as republican over democrat by a margin of 9 points and were equally likely to identify as liberal and conservative. By contrast, Jews in the study were found to identify as a Democrat by a margin of 40 points and liberal by a margin of 27 points. Mazur also looked at economic success. When using a question introduced in 1972 about whether one’s income was higher than 25,000 dollars, Jews were found to be somewhat less likely than controls to answer “yes”. However, using a question introduced in 1998, Jews were found to be twice as likely as controls to have an income of more than 110,000 dollars, suggesting that Jews today are both far more liberal and more wealthy than we would expect on the basis of them being highly educated and living in large cities. (However, it should be noted that both questions are problematic due to their treating income as a dichotomous variable rather than a continuous one). It is also worth noting that NYC is both the biggest city in America and the largest city with the most Jews. Yet, Jews vote democrat by smaller margins in NYC than they do nationally, making the claim that living in large cities explains Jewish leftism even more implausible (Heilman 2016). With respect to educational attainment, it should also be noted that Jews typically have a four year degree and this is the level of educational attainment which most strongly predicts someone being republican. So, like IQ, educational attainment actually increases the need for an independent explanation of Jewish political ideology (Pew, 2016; Last, 2018). It’s also worth mentioning that Lener et al. (1989) found Jewish elites continued to be to the left of gentile elites after controlling for the specific occupation they were in, as well as the respondents sex, age, socio-economic status, and whether they were from the south. To be clear, I am not denying that these other variables play some role in Jewish success or political ideology. Rather, I am merely claiming that none of these explanations give us good reason to think that ethnocentrism does not also play a significant role, especially in light of the positive evidence in favor of ethnocentrism as a partial explanation.

Conclusion

To end this post, let’s return to American history. Recall that Jews (and Catholics) displaced an American intellectual elite which used to be primarily comprised of liberal protestants. The fall of WASP rule then shifted the elite in a leftist and egalitarian direction. We might therefore ask what differentiates Jewish (and Catholic) elites from WASP elites which led to this difference in ideology. Returning to intelligence, in the only study I know of to directly compare the IQ scores of these groups, the mean IQ of Anglicans in America was found to be slightly higher than that of Jews (and significantly higher than that of Catholics).

(Nyborg, 2008)

(These values are inflated because non-whites were excluded. This and other possible sources of inflation may throw off the absolute values presented but should not impact the rank order of groups). Similarly, data from Pew finds that the educational attainment of Jews and Anglicans is basically equal.

Murphy (2016)

So socio-economic status and intelligence are unlikely to be an important part of the answer. I’ll finish this post by making an obvious suggestion: Jews (and Catholics) saw themselves as part of “the other” and so it made sense for them, from a self interested perspective, to take on leftist and egalitarian ideas. By contrast, nativism and elitism was (relatively more) rational for the old elite given their group interests. Thus, 20th century America saw its institutions be captured by “the other”. Since then protestants have adapted, to some degree, to this new environment. Meanwhile, we’ve been living with the consequences of the still on-going process of transforming the country so as to conform with the self-interested ideologies of an ever expanding list of traditional minorities with Jews being the minority in this set probably most strongly represented (and certainly most over-represented) at the very top tier of power.