In the run-up to Michigan’s presidential primary on Tuesday, President Biden has stayed out of the state, where he is facing a campaign from liberal activists frustrated with his enduring support for Israel in the war in Gaza.

But another Democrat jumped into the contentious debate tearing at the seams of the party’s coalition.

Representative Ro Khanna of California last week assumed the unofficial role as mediator between Democrats disaffected by Mr. Biden’s Middle East policies and Biden allies like himself. He met with students, Arab American leaders and progressive voters, many of whom said they were, at least for now, withholding their support from Mr. Biden.

He was blunt about his takeaway.

“We cannot win Michigan with status quo policy,” Mr. Khanna, who has pushed for a cease-fire, said an interview, adding that a shift should come in “a matter of weeks, not months.”

“Every day that goes by where we’re seeing the bombing of women and children on social media or cable news is not a good day for our party,” he said.

Mr. Khanna’s assessment is the latest warning sign for Mr. Biden about a swing state he won narrowly in 2020. The state is home to a large and increasingly discontent Arab American community, whose leaders have been pressing the White House for months to call for a cease-fire in a war that has left some 29,000 people dead in Gaza since Hamas attacked Israel on Oct. 7. In recent weeks, activists have begun urging Democrats to register their anger by marking their primary ballots as “uncommitted” rather than voting for Mr. Biden.

Mr. Biden last campaigned in the state at the beginning of this month, when he spoke to members of the United Auto Workers union in Warren, Mich., and faced protests from some pro-Palestinian activists. Vice President Kamala Harris also faced protesters last week when she came to discuss abortion policy at a round table in Grand Rapids, Mich., far from the Detroit metropolitan area where much of the war-related discontent is centered.

A handful of other Democrats, including Senator Amy Klobuchar of Minnesota and Representative Joyce Beatty of Ohio, stumped on the president’s behalf in Michigan over the weekend.

Mr. Khanna, a four-term congressman who has sought to raise his national profile in recent years and who backed Senator Bernie Sanders of Vermont for president in 2020, often serves as a surrogate for the Biden campaign and has popped up in New Hampshire and South Carolina to champion him ahead of recent Democratic primaries. But he said that his attendance at last week’s meetings in Michigan was in his personal capacity and not as a Biden surrogate — though the visit was approved by the Biden campaign.

Mr. Khanna fielded questions about the war from students at the University of Michigan. He attended a rally on getting corporate money out of politics alongside Representative Rashida Tlaib of Michigan, the sole member of Michigan’s congressional delegation backing the “uncommitted” efforts. And he met with elected and community leaders withholding their support for Mr. Biden.

In public remarks and private conversations, Mr. Khanna said that Democrats needed to better acknowledge the party’s shifting base and the concerns about the conflict, pointing to Michigan’s substantial young, Black and Arab American electorates.

But whether he can actually push the president to shift his policy on the war is unclear. Mr. Biden has not called for a permanent cease-fire, even as he has said that Israel should do more to prevent civilian casualties.

On Friday, Mr. Biden’s administration reversed Trump-era policy on settlements in the occupied West Bank when Secretary of State Antony J. Blinken called new settlements “inconsistent with international law.” That may not be enough to appease his detractors in Michigan, who said at rallies over the weekend that rebuilding ties with the administration would at least require a permanent cease-fire.

“There has to be some change in policy, and then once we get the change in policy, then there’s got to be some time for healing,” Mr. Khanna acknowledged in a conversation with Mika’il Stewart Saadiq, an imam in Detroit, who backed Mr. Biden ahead of the 2020 primary but planned to vote “uncommitted” on Tuesday.

“You have to give us something to campaign for,” Mr. Saadiq told Mr. Khanna, pointing to a cease-fire call and recognition of a Palestinian state. Otherwise, he added, “we’re in trouble.”

During meetings, Mr. Khanna peppered attendees with questions about what they wanted out of the White House, and what it would take to ensure Mr. Biden won Michigan. He met with leaders including Mayor Abdullah Hammoud of Dearborn, who refused a meeting with Mr. Biden’s campaign manager last month.

Former Representative Andy Levin of Michigan, another supporter of the “uncommitted” effort, saw a similarly grim picture for Democrats, The Associated Press reported, telling Mr. Khanna that if the election were tomorrow, “it would be a disaster for Democrats.”

Mr. Khanna is not supporting the movement to vote “uncommitted” — he said that if he were a Michigan resident, he would vote for Mr. Biden. And he is not among those who say the campaign is only teeing up former President Donald J. Trump for a victory in the state, as the state’s governor, Gretchen Whitmer, has suggested in recent days.

Mr. Trump won Michigan in 2016 by over 10,000 votes, the amount of support that backers of the “uncommitted” effort say they are aiming to receive on Tuesday.

“I have admiration for people who are using their rights as an American citizen to cast a ballot in a way that they think will bring a policy change,” Mr. Khanna said.

Supporters of the “uncommitted” campaign reject the notion that they are helping to elect a former president who campaigned on anti-Muslim rhetoric.

“It’s incredibly disrespectful when people say the communities that have felt the impact of Donald Trump more than anyone else don’t understand the danger of Donald Trump — it’s actually the inverse,” Abraham Aiyash, the Democratic majority leader in the Michigan House of Representatives, said after speaking with Mr. Khanna and another state representative, Ranjeev Puri.

“We absolutely understand it,” he continued, “and I think the question then becomes for the White House, if a community is telling you, ‘We know how dangerous Donald Trump is, but what you are doing in this moment is an abject moral failure,’ then that has to resonate in some capacity.”

For some, Mr. Khanna’s presence demonstrated how Democrats supporting Mr. Biden could navigate backlash to his administration’s policy. Adam Lacasse, a co-chairman of the College Democrats at the University of Michigan, said that he was impressed by the way Mr. Khanna “reconciles supporting a cease-fire and supporting President Biden because that’s something that a lot of students either support typically one or the other, but not both.”

Asked how he balances supporting the president and acknowledging his critics’ concerns, Mr. Khanna told The New York Times that “the biggest thing I can do is help get a shift in foreign policy, which, in my view, is what we need to win back these voters.”

Yet the meetings perhaps also served as a way for Mr. Khanna to boost his own image in a battleground state: In conversations, Mr. Khanna often slipped in points about his economic platform or accomplishments he had brought to his district.

On whether he had any presidential aspirations of his own, Mr. Khanna was noncommittal. “Who knows what the future holds?” he said. “What I would say, though, is, I will be one of the advocates for our party moving in a direction that recognizes the modern Democratic coalition.”