The Democratic Party’s yearslong unity behind President Biden is beginning to erode over his steadfast support of Israel in its escalating war with the Palestinians, with a left-leaning coalition of young voters and people of color showing more discontent toward him than at any point since he was elected.
From Capitol Hill to Hollywood, in labor unions and liberal activist groups, and on college campuses and in high school cafeterias, a raw emotional divide over the conflict is convulsing liberal America.
While moderate Democrats and critics on the right have applauded Mr. Biden’s backing of Israel, he faces new resistance from an energized faction of his party that views the Palestinian cause as an extension of the racial and social justice movements that dominated American politics in the summer of 2020.
In protests, open letters, staff revolts and walkouts, liberal Democrats are demanding that Mr. Biden break with decades-long American policy and call for a cease-fire.
The political power of the Israel skeptics within the party is untested, with more than a year remaining until the 2024 presidential election. Their efforts have been fractious and disorganized, and they have little agreement on how much blame to lay at Mr. Biden’s feet or whether to punish him next November if he ignores their pleas.
And yet Mr. Biden is already struggling with low Democratic enthusiasm, and it would not take much of a slip in support from voters who backed him in 2020 to throw his re-election bid into question. His margin of victory in key battleground states was just a few thousand votes — hardly enough to spare a significant drop-off from young voters alienated by his loyalty to a right-wing Israeli government they see as hostile to their values.
At its heart, the turbulence over Israel is a fundamental disagreement over policy, setting it apart from challenges like voters’ dissatisfaction with the economy, which Mr. Biden’s allies believe can be solved with better messaging. The president, who has for decades positioned himself in the middle of his party and has navigated Democrats’ ideological and generational divide for the first half of his term, now confronts an issue that has no easy middle ground.
Perhaps most concerning for Mr. Biden is that in the halls of Congress, the most critical Democratic voices are Black and Hispanic Democrats who helped fuel his 2020 victory. As of Thursday, all 18 House members who had signed onto a resolution calling for an “immediate de-escalation and cease-fire in Israel and occupied Palestine” were people of color.
“We process pain, deprivation and cruelty personally, having either encountered it in our current lives or having had historical connections to it with our ancestors,” said Representative Bonnie Watson Coleman of New Jersey, one of the cease-fire resolution’s co-sponsors. “So we understand that cruelty and war and violence do not have positive outcomes.”
For Democrats in Congress and in liberal groups in Washington, pressure to oppose Mr. Biden’s Israel policy is bubbling up from younger, more progressive staff members who have grown up in an environment more doubtful about Israel.
Hundreds of former staff members who worked for the presidential campaigns of Senator Bernie Sanders of Vermont and Senator Elizabeth Warren of Massachusetts this week signed open letters urging them to introduce a similar cease-fire resolution in the Senate.
The senators have resisted such calls, but Mr. Sanders this week urged a “humanitarian pause,” a position that some other liberal lawmakers and groups have begun to embrace and that Secretary of State Antony J. Blinken has said “must be considered.”
Other progressive lawmakers, however, argue that such a pause does not go far enough.
“A humanitarian pause, what is that?” said Representative Cori Bush of Missouri, who introduced the cease-fire resolution. “We need a cease-fire. We need to stop bombs from being dropped on hospitals and on schools and communities.”
At MoveOn, the liberal activist group that endorsed Mr. Biden in April, younger staff members revolted after the organization issued an initial statement condemning the Hamas attack that ignited the current war without addressing Israel’s conduct toward the Palestinians.
“There was a vocal percentage of our staff that did express their opinions,” Rahna Epting, MoveOn’s executive director, said in an interview. “I reminded them that ultimately we need to go to the members and see where they are.”
MoveOn’s latest statement on the war, a petition, underscores the humanitarian crisis in Gaza and states that “President Biden and our leaders must publicly call for an immediate cease-fire.”
Differences over Israel policy have caused conflict even among the nation’s top union officials. The executive committee of the A.F.L.-C.I.O. addressed the issue during a tense meeting on Monday night that was dominated by a 30-minute anti-Israel monologue from the president of the American Postal Workers Union, who described himself as an “anti-Zionist Jew.”
Many on the left, however, acknowledge that Mr. Biden remains preferable to a Republican alternative in 2024. Ms. Epting said MoveOn could “support President Biden and apply pressure to him at the same time.”
Matt Duss, a former foreign policy adviser to Mr. Sanders who is among the most vocal proponents of a cease-fire, condemned Mr. Biden’s hug-Israel approach — but said he would not withhold support for Mr. Biden next year over the differences.
“Is this worth losing an election to Trump and all that would bring? No,” Mr. Duss said. “At the same time, I think it’s on Biden to understand where his voters are.”
For many on the left, sympathy for the Palestinian cause stems from the same feelings of powerlessness that fueled the protests after George Floyd’s murder three years ago.
“There’s definitely a direct correlation,” said DaMareo Cooper, a co-executive director of the Center for Popular Democracy, a collective of progressive community groups. “When we say Black Lives Matter, what’s really being said inside of that statement is a history of oppression.”
Mr. Biden’s allies dismissed the prospect that his position on Israel would damage him in 2024. Representative Ritchie Torres of New York, one of the most outspoken Democratic supporters of Israel in Congress, said he had been offended by cease-fire calls that did not also demand that Hamas release American and Israeli hostages.
“We have to be careful not to mistake a visible vocal minority for a majority,” Mr. Torres said. “The critics of Israel have far more power on social media than in the real world.”
Demonstrations against U.S. policy in Israel have spread from the Capitol and college campuses — Cornel West, the left-wing independent presidential candidate, appeared at a rally on Wednesday at the University of California, Los Angeles — to high schools across the country. Students at several high schools in Northern Virginia walked out of classes this week in a “Humanitarian Walkout Week.” The presidents of George Washington and Emory Universities, among others, condemned anti-Israel slogans chanted at rallies and projected on buildings.
An array of liberal groups have adopted the Palestinian cause. This week in New York, one protest sign read, “Reproductive justice means justice for Palestine.” At another demonstration in Manhattan, hundreds marched under the banner of “Queers for Liberation in Palestine.”
“I feel very betrayed by Biden,” said Angela Balya, 28, a protester in Manhattan who said she had volunteered for the Biden campaign in 2020. “I definitely will not be voting for him again.”
The Sunrise Movement, a coalition of young, progressive climate activists that mobilized on behalf of Mr. Biden’s campaign in 2020, is one such group that has called for a cease-fire. Some in the organization have been “raising questions” about whether they and other young people will mobilize for Mr. Biden again, said Michele Weindling, the group’s political director.
“If the Democratic Party and President Biden continue to send weapons and military support to Israel, it threatens to lose our generation, and that’s a very dangerous choice to make ahead of a critical election year,” Ms. Weindling said.
The United States’ support for Israel is unpopular with voters under 35, polling has shown, and students at dozens of colleges on Wednesday afternoon walked out of class as part of a nationwide mobilization effort by the group Students for Justice in Palestine.
“President Biden has shown to people that there’s virtually no difference between Republicans and Democrats on the question of the mass atrocities being leveled against Gaza,” said Kaleem Hawa, who has helped organize student protests with the Palestinian Youth Movement.
Few liberal organizations have had as raw a discussion about Israel as the A.F.L.-C.I.O. did at the Monday night meeting of its executive council.
Mark Dimondstein, the president of the postal union, argued that Israel and the Palestinian territories should be combined into a single state. He called for the A.F.L.-C.I.O. to demand a cease-fire, according to four people familiar with the contents of the meeting.
No other labor leader in the meeting offered vocal support for his position.
Randi Weingarten, the president of the American Federation of Teachers, who is married to a rabbi, responded by asserting Israel’s right to defend itself, the people familiar with the meeting said. Ms. Weingartensaid she backed establishing an independent Palestinian state alongside Israel. “That has been part of the Democratic platform for as long as I can remember,” she said.
Mr. Dimondstein, whose union represents more than 220,000 postal workers, saidhe was “not part of the Democratic Party” and, like Ms. Weingarten, declined to discuss the A.F.L.-C.I.O. call.
“I’m not answering your questions,” he said.
Some of the left-wing demonstrators’ demands fall well outside the American political mainstream.
“The occupation and the existence of Israel is not peaceful; there is no ‘maintaining the peace’ with a violent settler state,” read one bullet in an online document posted by the Democratic Socialists of America and shared widely this week among pro-cease-fire organizers.
At a protest in Manhattan on Wednesday, protesters chanted, “We don’t want no two states, we want all of it.”
Susan C. Beachy contributed research.