As progressive students equate Israel with racial discrimination, major American Jewish institutions have sought to counter this messaging. At the 2017 annual meeting of the Jewish Federations of North America — the umbrella group for hundreds of Jewish philanthropic organizations, which have a combined endowment of more than $16 billion — one of the panels convened was titled “PRO-gressive and PRO-Zionist: Can You Be Both?” A leading Israel advocacy group on campus, the David Project, has held outreach events for Latinos and African-Americans. After the 2015 divestment resolution at Stanford, the white Jewish Agency Israel fellow at Hillel was replaced by a black one.

At an earlier apartheid-wall protest at Michigan, Becca Lubow, the head of J Street U at the university, stood with other pro-Israel students, one of whom, because of J Street’s criticisms of Israel, called her a kapo, a Jewish collaborator with the Nazis. Last fall, when asked by pro-Israel students if she was attending the demonstration, she said no. “Hillel ignores us all year and then becomes our friend during pro-Palestinian events like the divestment vote,” she told me.

Lubow said she felt a “sense of personal responsibility for what Israel is doing to the Palestinians — like it’s almost the personal fault of me and my family and the communities I’ve supported all my life, and they’re doing it in my and our name.” She wondered if she should leave Hillel or J Street, which has resisted years of entreaties from some of its student leaders to move from rhetorical condemnations of Israeli policies to advocating economic and diplomatic pressure. For now, she said, she was staying in J Street U because she believed she could be more effective by influencing her own community. “There’s an expression people use when something racist happens: ‘White people, get your people.’ I’m trying to get my people,” she said. Three days later, she emailed me that J Street U had left the Israel cohort of the Michigan Hillel.

Politicians speaking on Israel-Palestine used to worry primarily about attacks from pro-Israel media and activist groups; now progressives are starting to feel some heat from the pro-Palestinian side. During the 2018 campaign, Tlaib, the first Palestinian-American woman to be elected to Congress, was denounced on the Electronic Intifada website by the site’s co-founder, the Palestinian-American B.D.S. activist Ali Abunimah, for receiving an endorsement from J Street. She later declared her support for a one-state solution, though she denies that it was because of Abunimah’s denunciation. J Street withdrew its endorsement. Alexandria Ocasio-Cortez came under attack on social media from an otherwise adoring progressive base after she responded to a question about her “massacre” tweet by proclaiming herself a “firm believer” in a two-state solution and saying she “absolutely” believes in Israel’s right to exist.

At a town hall in 2017, Senator Kirsten Gillibrand and Senator Elizabeth Warren, each of whom is now running for president, came out against the Israel Anti-Boycott Act. Each faced pointed questions from members of Jewish Voice for Peace, which had organized a campaign to pressure politicians to oppose the bill on the grounds that it infringed on the First Amendment. Gillibrand withdrew her name as a sponsor of the bill, and Warren declared that she opposes B.D.S. but that “outlawing protected free speech activity violates our basic constitutional rights.” Later that year, in the House, Representative McCollum put forward a bill demanding that the secretary of state certify that “United States funds do not support military detention, interrogation, abuse or ill-treatment of Palestinian children.” Though it received no public support from J Street — previously considered the arbiter of the outer limit of what Democrats would back — 30 Democrats co-sponsored the bill.

In December, after Tlaib won the Detroit congressional seat long held by John Conyers, she announced that she would not go on the free Aipac-led trip customarily taken by freshman members and would instead lead her own delegation to the West Bank, where her grandmother lives. She also declared her support for the B.D.S. movement, making her the second member of Congress to do so. The other is her fellow Muslim congresswoman, Ilhan Omar. In February, the bill sponsored by Senator Marco Rubio that would give federal backing to state anti-B.D.S. laws came up for a vote in the Senate. Though it passed, almost half of the 47 members of the Democratic Caucus in the Senate voted against it. The list included all the senators who had filed a statement of candidacy for president in 2020: Warren, Gillibrand, Kamala Harris and even Cory Booker, who has a largely pro-Israel voting record and is a sponsor of the Israel Anti-Boycott Act.

“We’re one moment away from this changing, once someone breaks through the fear factor,” Rhodes said, referring to U.S.-Israel policy, when I spoke to him in October. He recalled that before Obama’s first presidential campaign, Democrats were afraid to challenge the United States’ embargo of Cuba, particularly given the historical support for the embargo among many Cuban-Americans in Florida, a battleground state. “Once we showed that we were willing to break that Cuba fear factor, the party fell in line behind a totally different Cuba policy.” When I spoke to him again in March, he added: “If you look beyond the Ilhan Omar controversy, too, Democratic candidates are comfortable strongly criticizing the prime minister and his policies.” James Zogby, the Sanders appointee to the D.N.C. platform drafting committee in 2016, says that standing for Palestinian rights is guaranteed to be a major topic in the 2020 election: “It’s a smell-test issue. If you go to young people, they know you stink if you don’t talk about it right.” A senior Democratic staff member on Capitol Hill told me: “People like Ilhan Omar, Rashida Tlaib and Bernie Sanders have opened the floodgates on this issue. It may be painful for the party as we move in a more progressive direction. But we’ll come out in a better place — a more moral and evenhanded place — in the end.”