The United Automobile Workers union endorsed President Biden on Wednesday, delivering an influential boost as he faces a battle against former President Donald J. Trump to win the support of labor groups.
Mr. Biden, who calls himself the “most pro-union president in history,” delighted striking U.A.W. workers but angered auto industry executives when he appeared on a picket line with workers last fall. On Wednesday, he appeared in front of a national conference of autoworkers to tell them that he had been proud to do it.
“Let me tell you something I learned a long time ago,” Mr. Biden said. “If I’m going to be in a fight, I want to be in the fight with you, the U.A.W.”
In earlier remarks, Shawn Fain, the U.A.W. president, told the crowd that Mr. Biden had the track record to help working-class people organize for higher wages, better retirement benefits and health care.
“This election is about who will stand up with us and who will stand in our way,” Mr. Fain said after a lengthy speech comparing Mr. Biden’s past pro-union speeches with Mr. Trump’s lack of support and appearances at nonunion facilities. He called Mr. Trump a “scab” — shorthand for someone who undercuts the power of a union, such as by replacing a striking worker.
“If our endorsement must be earned, Joe Biden has earned it,” Mr. Fain said.
The value of the endorsement, which the U.A.W. put off last year over concerns about Mr. Biden’s commitment to promoting union jobs in electric-vehicle manufacturing, may be less about persuading members to back Mr. Biden 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.
