The United Automobile Workers union will endorse President Biden on Wednesday, delivering an influential boost to a president who faces a battle against former President Donald J. Trump to win the support of labor groups, according to a person familiar with the plan.
Mr. Biden, who appeared on a picket line with striking union workers in the fall, was to provide the keynote speech at a union conference in Washington and address “the top issues facing working-class Americans,” according to a media advisory for the event.
The union was expected to announce the endorsement at the event, according to the person familiar, who spoke on the condition of anonymity to discuss the plan.
The value of the union’s endorsement to Mr. Biden may be less about persuading members to back him than in motivating them to vote. The union has estimated that only about 30 percent of its members supported Mr. Trump in 2016. But without the union’s formal backing and investments in turnout, Mr. Biden could suffer a drop-off in members who show up to vote in critical swing states like Michigan.
Before the president’s speech, several members said that they had expected the endorsement to go to Mr. Biden, and that a directive from the U.A.W.’s president, Shawn Fain, would decide which way they would vote. But several also said that they had seen how the war in Gaza had divided their ranks.
“There’s people in these lines that are hurting,” said Daniel Dunbar, 67, a retired autoworker from Flint, Mich. “They have family over there, and they’re afraid for them.”
Mr. Fain has been a vocal critic of Mr. Trump, and criticized some Republican policies as divisive and harmful when he spoke at the conference on Monday.
He said that the party takes stances against transgender and gay people “so they don’t have to talk about who you work for, where the profits go and who benefits.” He also criticized Republican attack lines over immigration into the United States.
“Right now, we have millions of people being told that the biggest threat to their livelihood is migrants coming over the border,” Mr. Fain said. “The threat we face at the border isn’t from the migrants. It’s from the billionaires and the politicians getting working people to point the finger at one another.”
Mr. Biden, who calls himself the “most pro-union president in history,” has appeared at several U.A.W. events to prove his bona fides with the group’s leadership and rank and file.
“I’ve been involved in the U.A.W. longer than you’ve been alive,” the president, then 80, told the boisterous crowd at an event in Illinois in November, after the union reached an agreement with Ford, General Motors and Stellantis on a contract that included pay increases and reopened a plant in Belvidere, Ill.
At that event, he castigated Mr. Trump for insisting that electric vehicles would lead to the loss of thousands of manufacturing jobs.
“Well, like almost everything else he said, he’s wrong,” Mr. Biden said at the time. “And you have proved him wrong. Instead of lower wages, you won record gains. Instead of fewer jobs, you won a commitment for thousands of more jobs.”
Union officials often say Mr. Biden has been more vocal than any president in decades in backing organized labor. He appeared in a video as Amazon workers in Alabama sought to unionize, warning that “there should be no intimidation, no coercion, no threats, no anti-union propaganda,” and called out Kellogg for its plans to permanently replace striking workers. (The strike was resolved before the company took that step.)
The U.A.W. was early to support Mr. Biden’s green energy policies, but became frustrated by the lack of support for unionized auto-industry jobs in the Inflation Reduction Act, the major climate bill that the president signed in 2022.
“The E.V. transition is at serious risk of becoming a race to the bottom,” Mr. Fain wrote in an internal memo last May announcing that the union planned to withhold an endorsement of Mr. Biden, at least temporarily. “We want to see national leadership have our back on this before we make any commitments.”
The following month, Mr. Fain expressed frustration that the Biden administration had given Ford a $9 billion government loan to build three electric-vehicle battery plants in Tennessee and Kentucky without any commitment by the company to create high-wage union jobs there.
Mr. Biden’s team redoubled its efforts to engage the union. He tapped Gene Sperling, a longtime Democratic policy hand who is from Michigan, to serve as his liaison to the union and the auto industry. In August, the president’s administration unveiled $12 billion in grants and loans for electric vehicle manufacturing, which would give priority to companies that support well-paying jobs in unionized areas. Mr. Sperling was also in regular contact with senior union officials in the run-up to the strike and during the strike itself.
Mr. Biden’s decision to appear on the picket line in Michigan angered auto industry executives, according to administration officials, who said that the president was nonetheless determined to make clear where he stood in the labor conflict.