WASHINGTON --  

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

鈥淚鈥檓 proud to stand up here and announce that the UAW is endorsing Joe Biden for president of the United States,鈥 said UAW president Shawn Fain after he laid out the reasons for the endorsement.

Biden, a Democrat, is working to sway blue-collar workers his way in critical automaker swing states such as Michigan and Wisconsin, hoping to eat into the advantage that former president Donald Trump has enjoyed with white voters who are without a college degree. Labour experts said that the UAW usually endorses candidates later as it contains a mix of Democratic, Republican and unaffiliated voters.

鈥淚鈥檓 honoured to have your back and you have mine," Biden said. "That鈥檚 the deal.鈥

Biden spoke as the union closes out a three-day gathering in Washington, D.C., 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 will speak as the union closes out a three-day gathering in Washington, D.C. 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 labour-friendly leader in American history, and 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.

鈥淗e heard the call and he stood up and he showed up,鈥 Fain said of Biden鈥檚 historic picket line appearance. He drew a contrast between Biden鈥檚 pro-union efforts and Trump, who he said was anti-union.

鈥淒onald Trump is a scab鈥 he yelled to boos and hisses from the crowd. 鈥滵onald Trump is a billionaire and that's who he represents."

鈥淭his 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鈥檚 what this choice is about,鈥 Fain said.

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.鈥

In his speech Wednesday, Fain said Biden had earned it.

But 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.

鈥淚 hope they don鈥檛 get amnesia,鈥 Loveless said, 鈥渃ome Election Day.鈥

William Louis of Groton, Conn., another member, said that while he is 鈥渇ed up with politicians鈥 he will reluctantly vote for Biden, though he said the president had not fully earned members鈥 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.鈥

Leo Carrillo, a member from Kansas City, said Biden鈥檚 appearance on the picket line showed that 鈥渉e was there for us,鈥 and helped him to decide to vote for Biden in November.

鈥淔or me it meant a lot鈥 that a sitting president would show that level of solidarity to autoworkers, Carrillo said. 鈥淏ut there鈥檚 more work to be done,鈥 he said, pointing to the PRO Act 鈥 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 鈥渃easefire now鈥 during Fain鈥檚 afternoon speech Monday. The union called for a ceasefire in Gaza in December.

鈥淩ight now he鈥檚 done nothing to earn my vote,鈥 King-Slutzky said, because 鈥渉e has not acted with urgency to stop the genocide in Gaza.鈥

The union has a lengthy process to determine its endorsements that involves the rank-and-file, but it鈥檚 unclear how far along that is.

Fain, the first UAW president directly elected by members, took office after a huge bribery and embezzlement scandal that ended with two union presidents serving prison time. So he鈥檚 making sure to follow union procedures on the endorsement and show that members made the decision, even though there鈥檚 no way the UAW would back Trump, said Brian Rothenberg, a former union spokesman.

The UAW, with roughly 380,000 members, is normally one of the last unions to endorse presidential candidates, Rothenberg said. For example, the union didn鈥檛 endorse Biden in 2020 until April 21.

In a November interview with The Associated Press, Fain made clear that he personally supports Biden, as he railed against Trump.

Fain pointed to Biden's trip to the GM parts warehouse, which is believed to be the first time a sitting president appeared with union picketers.

About that same time, Trump held a rally at a nonunion auto parts maker near Detroit, which Fain said was odd. Biden鈥檚 administration also supported the union鈥檚 bid to persuade Stellantis to reopen a shuttered plant in Belvidere, Illinois, and joined Fain in the city 113 kilometres northwest of Chicago to celebrate its reopening, Fain said.

Trump, Fain said, didn鈥檛 come to Detroit when the UAW was on strike while he was president in 2019, and he talked about moving auto jobs to southern states where pay is lower.

鈥淎ctions speak louder than words,鈥 Fain said. 鈥淏ut this process belongs to the membership, and we鈥檒l make those decisions when it鈥檚 time.鈥

Art Wheaton, director of labour studies at Cornell University, said he would be surprised to see the union endorse Biden at this point in the campaign. The UAW, he said, would hold more leverage over legislation and other items if it waits until closer to the election to announce who it's backing.

鈥淭here鈥檚 no big hurry in terms of the UAW and their timeframe,鈥 he said.

Rothenberg said a union endorsement is important because polling shows many UAW members are often undecided in the spring before a presidential election.

Internal UAW polling typically shows that in the spring and early summer, 30 per cent of members support the GOP, 30 per cent support Democrats and the remaining 40 per cent swing between parties, he said. By Election Day, members and UAW retirees usually vote 60 per cent Democratic, said Rothenberg, now a public relations consultant in Columbus, Ohio.

The endorsement also could sway nonunion blue-collar white males, who have been voting more for Republicans than in the past, Rothenberg said.

Associated Press writer Zeke Miller contributed to this report. Krisher reported from Detroit.