Mr. Bloomberg not-so-subtly sought to distinguish himself from Senator Bernie Sanders of Vermont, who is also Jewish and who recently took the lead in Iowa, according to a recent New York Times/Siena College poll of likely caucusgoers. Mr. Bloomberg, the billionaire former mayor of New York City, took aim not only at Mr. Sanders’s Israel policy but also at his democratic socialism.

“Now, I know I’m not the only Jewish candidate running for president,” Mr. Bloomberg said in his speech on Sunday afternoon, delivered in a ballroom with a roving blue spotlight and Israeli techno and music by the rapper Pitbull setting the mood. “But I am the only one who doesn’t want to turn America into a kibbutz.” The audience whooped.

The crowd of several hundred people included prominent business figures, former local politicians and many with personal connections to the candidate, some of whom had traveled from New York. Ari Ackerman, an owner of the Miami Marlins baseball team, was among them, having helped to rally young Jewish support for two of Mr. Bloomberg’s mayoral runs.

“Quadrupling funding for religious institutions, creating a Holocaust program in schools so people are educated about what happened, bringing together the presidents of different universities to create a coalition to battle anti-Semitism — this is what he’s talking about,” Mr. Ackerman said.

The speech on Jewish identity was an unusual move for Mr. Bloomberg, a secular Jew who has long not been religiously observant. He has previously turned to his Judaism in competitive campaign moments, as in his 2005 mayoral re-election campaign when he addressed Hasidic Jews in Borough Park, Brooklyn, on a stage dotted with blue balloons that read “Mike the Mensch.”