In a country where anti-Semitic attacks have spiked and the president has sometimes hesitated to condemn neo-Nazis, two men who celebrated their bar mitzvahs in the 1950s suddenly want to talk about their Jewishness.

“I know I’m not the only Jewish candidate running for president,” Mike Bloomberg, the former New York City mayor, told a packed synagogue here today, referencing his Democratic-primary rival Senator Bernie Sanders. “But I am the only one who doesn’t want to turn America into a kibbutz.” For the first time in American history, this niche joke fit neatly into a campaign for the White House. And for the first time in American history, there’s a good chance that a Jewish candidate for president will beat another Jewish candidate to become a major party’s nominee.

Before this campaign, neither Bloomberg nor Sanders spent much time publicly discussing, let alone celebrating, their Jewishness. But a few weeks ago, Sanders was ice-skating during a Hanukkah party at a Des Moines rink, lighting a giant menorah with a blowtorch and mouthing the words to a few of the Hanukkah songs. And Bloomberg was here, making a direct appeal to Jewish voters complete with deli references and Catskills-style rim shots. He quoted Leviticus (a book he identified by its Hebrew name, Vaykira) in Hebrew and said, “Lo ta-amode, do not stand by idly while your neighbor’s blood is shed,” stumbling slightly over the pronunciation, much like how he misplaced the emphasis on the word kibbutz.

To those who know Bloomberg well and even spent years working for him, this is a surprising turn. As mayor, he was more of the stop-by-synagogue-on-Rosh-Hashanah kind of observer, not the guy who’d make a not-so-subtle reference to Donald Trump as “a pharaoh who knows not Joseph,” and speak about “standing together, rejecting demagogues who try to seduce us by playing us against each other, and uniting behind the only shield that can protect us: our common values as American citizens and our common humanity as God’s children.” Bloomberg went all in, going directly from “When Moses descended from Mount Sinai, he smashed the golden calf and raised high a tablet of laws,” to noting that Monday is “the 75th anniversary of Auschwitz’s liberation,” and recalling his own visit to the death camp a few years ago.

This wasn’t a speech like any presidential candidate has delivered before—and that includes Sanders. Before launching his 2020 campaign, Sanders rarely discussed his Jewish roots, publicly or privately. Sanders superfans know he spent a few months after college in Israel working on a kibbutz, but he’s talked about that more through his socialism than through any connection to the Jewish state. For years, Sanders referred to his father as a “Polish immigrant,” which some saw as a pointed erasure of his identity—when Eli Sanders arrived in America, after all, his passport from the Polish government would have listed his nationality as “Jew.” Jewish leaders have criticized him for decisions like speaking at the evangelical Liberty University in 2015 on the first day of Rosh Hashanah, the Jewish New Year.