“I am very proud of being Jewish and that is an essential part of who I am as a human being,” Vermont Senator and presidential hopeful Bernie Sanders says in a new campaign ad he tweeted this weekend on the subject of his Jewishness. It signaled the latest evidence of a marked change from 2016, when Sanders was reticent to discuss his Jewish identity. But while Sanders is enjoying growth with many ethnic and racial groups, his message has not yet won him many Jewish supporters.

I’m very proud to be Jewish and I look forward to becoming the first Jewish president in the history of this country. pic.twitter.com/UOPvEomHNE— Bernie Sanders (@BernieSanders) February 17, 2020

In a way, it’s surprising, and not just because Sanders would be the first Jewish president of America if he wins. Jews have also historically supported the kind of leftist politics Sanders represents. There’s the old adage of famed Jewish sociographer Milton Himmelfarb that Jews earn like Episcopalians and vote like Puerto Ricans. It’s been a maxim of American Jewish politics for several generations, since the children and grandchildren of the first large waves of Jews from Eastern Europe began to move up the economic ladder. The civil rights movement, gay rights, and anti-war movements, which all came to be mainstream views of the Democratic Party, featured heavy participation by American Jews.

Image by Alex Zeldin | artist: Noa... Alex Zeldin | artist: Noah Lubin

So you might think a Brooklyn-born Jew, Senator Bernie Sanders, who has personally participated in a number of these movements, would have American Jews lining up behind him along with the many other Democratic primary voters who have pledged their support. And yet, what data we have shows that Sanders is not all that popular with Jews. And despite sweeping Iowa and New Hampshire and overtaking former Vice President Joe Biden, there appears to be no discernible shift yet in Jewish support for Bernie Sanders.

So why aren’t American Jews lining up behind him?

The answer is that Jews vote less like the grandchildren of their grandparents than they do like other well-off, educated liberals. It’s class, rather than ethnicity or history, that is increasingly determining their vote.

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But it’s always been circumstance. Over a century ago, as the ancestors of many Ashkenazi American Jews fled Tzarist Russia and the Austro-Hungarian empire, they arrived with little by way of formal education, capital, and English language skills. It’s why the Forward began in 1897 as a Yiddish-language socialist publication in New York. Many fled after the failed Russian revolution in 1905 as well, and came to America as committed socialists. Young leaders of the Bund, persecuted by Russian authorities, can be found on the roll calls of many American labor groups of that period.

It’s this Jewish political tradition that Sanders hails from, a self-identified socialist who has successfully positioned himself as the candidate of labor. It’s a robust Jewish tradition. While American anti-Semitism did not manifest in pogroms or coercive government programs designed to convert or ethnically cleanse Jews, there were significant social barriers to Jewish advancement. Universities such as Columbia, alarmed by the over 1.5 million Jews who by 1920 called New York home, began implementing quotas to ensure that White Anglo-Saxon Protestants would continue to dominate campus life. Many other esteemed universities, with the notable exception of Historically Black Colleges, implemented similar restrictions against Jewish applicants. Restrictions in many places also included employment discrimination as well as housing covenants, which were designed to keep minorities like Blacks, Catholics, and Jews from purchasing homes in white protestant neighborhoods.

For these reasons, Jewish politics were starkly left. And that heritage still informs Jewish voting patterns, with 80% of Jews voting Democratic in the 2018 midterms. The question is less where American Jews stand, but where they sit. Today, American Jews are financially successful and highly educated; nearly one in three American Jews holds a postgraduate degree, compared to fewer than one in 10 Americans. Liberals with that profile have their own voting habits.

We have seen it play out for months in the surveys conducted ahead of the Democratic presidential primary. While both Sanders and Senator Elizabeth Warren attract voters who self-identify as liberals, Warren has outperformed in national surveys with those who are highly educated high earners, while Sanders, who has the most pro-worker message, trails much of the field with this demographic.

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American Jews follow this trajectory. Polling as recent as January 2020 shows that American Jews are backing Biden and Warren, with small town mayor and self-positioned moderate Pete Buttigieg beating out Sanders.

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Jewish reticence for Sanders has a number of sources. Some may worry that any prominent Jew in the race could attract anti-Semitism. Others may feel alienated by Sanders’ online fans, many of whom have a reputation for harassing his critics. Then there are his surrogates, which include Linda Sarsour, who repeatedly antagonized American Jews, including with attempts to make Jews choose between Zionism and feminism, and by hosting a conference in which Sarsour sought to define and explain anti-Semitism to Jews.

And centrist and right-wing pro-Israel Jewish organizations who more closely watch the inside baseball of party politics were no doubt alarmed by Sanders’ 2016 Democratic platform fight in which he sent outspoken critic of Israel James Zogby to insert criticism of Israel’s occupation of Palestinian territory into the party platform. Sanders lost that fight in 2016. Should he become the Democratic nominee in 2020, there is good reason to expect more explicit criticism of Israel’s present trajectory to make it into the party platform and into American foreign policy.

Nevertheless, there are decades of data to suggest that while the predominately white collar American Jewish community may not fall in love with the Jewish socialist from Vermont, they will fall in their partisan line, and may even find some things about Senator Sanders relatable.

Predictions are hard, especially predictions about the future. What we know for certain should Sanders wins the nomination is that neither his Jewish critics nor his Jewish supporters will be won over by appeals to Jewish pride alone.

Alex Zeldin is a contributing columnist with the Forward.