U.S. President Joe Biden picked up the endorsement of the United Auto Workers on Wednesday as he addressed the powerful union’s political convention.

Biden, a Democrat, is pushing to sway blue-collar workers his way in critical automaking swing states such as Michigan and Wisconsin, hoping to cut into the advantage that Republican former President Donald Trump has enjoyed with white voters who don’t have a college degree.

Labor experts said that the UAW usually endorses candidates later as it has a mix of Democratic, Republican and unaffiliated voters.

“This November we can stand up and elect someone who stands with us and supports our cause, or we can elect someone who will divide us and fight us every step of the way. That’s what this choice is about,” UAW President Shawn Fain said in announcing Biden’s endorsement.

Biden will speak as the union closes out a three-day gathering in Washington to chart its political priorities. It will be his first political event since Tuesday’s primary vote in New Hampshire, where Trump cemented his hold on core Republican voters with a victory and Biden scored a write-in win.

Biden frequently bills himself as the most labor-friendly leader in American history, and he went so far as to turn up on a picket line with union workers at a GM parts warehouse in the Detroit area during a strike last fall.

FILE - U.S. President Joe Biden speaks to striking United Auto Workers on the picket line outside the Willow Run Redistribution Center, UAW Local 174, Sept. 26, 2023, in Van Buren Township, Michigan.

FILE – U.S. President Joe Biden speaks to striking United Auto Workers on the picket line outside the Willow Run Redistribution Center, UAW Local 174, Sept. 26, 2023, in Van Buren Township, Michigan.

“He heard the call, and he stood up and he showed up,” Fain said of Biden’s historic picket line appearance. He drew a contrast between Biden’s pro-union efforts and Trump, who he said was anti-union.

As recently as Monday, Fain was restrained in his comments, saying as the conference opened, “We have to make our political leaders stand up with us. Support our cause, or you will not get our endorsement.”

At this week’s conference, support for Biden among union members has varied from enthusiastic to uncertainty about whether to even vote come Election Day.

Caroline Loveless, a Waterloo, Iowa, resident and retired UAW member, said she would enthusiastically vote for Biden, recalling his appearance on a picket line during last fall’s strike. She said his appearance should remind union members that Biden is on their side.

“I hope they don’t get amnesia,” Loveless said, “come Election Day.”

William Louis, of Groton, Connecticut, another member, said that while he is “fed up with politicians,” he will reluctantly vote for Biden, although he said the president had not fully earned members’ vote given the current state of the economy.

Louis said Biden would get his vote because Trump, the likely Republican nominee, “was a terrible president.”

United Auto Workers union member Leo Carrillo, poses for a photograph on Jan. 23, 2024, in Washington. Carrillo, a member from Kansas City, said Biden’s appearance on the picket line helped him to decide to vote for Biden in November.

United Auto Workers union member Leo Carrillo, poses for a photograph on Jan. 23, 2024, in Washington. Carrillo, a member from Kansas City, said Biden’s appearance on the picket line helped him to decide to vote for Biden in November.

Leo Carrillo, a member from Kansas City, said Biden’s appearance on the picket line showed that “he was there for us,” and helped him to decide to vote for Biden in November.

“For me it meant a lot” that a sitting president would show that level of solidarity to autoworkers, Carrillo said. “But there’s more work to be done,” he said, pointing to the PRO Act — proposed legislation that would make it easier to unionize on a federal level. The legislation advanced to the U.S. Senate but does not have enough support to survive in case of a filibuster.

Biden could run into dissent, however, over his support for Israel in its war on Hamas in Gaza. Some younger members of the union were less enthusiastic about the president for that reason.

Johannah King-Slutzky, a Columbia University graduate student and member of the student workers union within the UAW, was one of several attendees who chanted “cease fire now” during Fain’s afternoon speech Monday. The union called for a cease fire in Gaza in December.

“Right now, he’s done nothing to earn my vote,” King-Slutzky said, because “he has not acted with urgency to stop the genocide in Gaza.”

The UAW has roughly 380,000 members.