WASHINGTON (AP) — President Joe Biden picked up an endorsement from the United Auto Workers union Wednesday, an important boost to the Democratic president's reelection bid as he pushes to sway blue-collar workers his way in critical auto-making swing states such as Michigan and Wisconsin.

"I'm honored to have your back and you have mine," Biden said to the cheering crowd. "That's the deal."

Biden spoke as the union closed out a three-day gathering in Washington to chart its political priorities. The event follows Tuesday's primary vote in New Hampshire, where Republican front-runner Donald Trump cemented his hold on core Republican voters with a victory and Biden scored a write-in win.

Biden has long billed himself as the most labor-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.

The president is hoping to cut into the advantage that 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.

"The days of working people being dealt out of a deal are over in this country as long as I'm president," Biden told the crowd. "I want to say to all of you thank you, thank you. I could not be more proud."

Union president Shawn Fain had demurred even earlier this week, but on Wednesday said Biden had earned the endorsement, contrasting what he said was the president's obvious support with Trump's trash talk and anti-union stance.

"He heard the call and he stood up and he showed up," Fain said of Biden's historic picket line appearance.

But when UAW went on strike against GM in 2019, Trump, then president, was silent. "He said nothing. He did nothing. Not a damn thing because he doesn't care about the American worker," Fain said.

Fain called Trump a "scab," a derogatory term for workers who cross union picket lines and work during a strike.

"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," Fain said.

Among union members, support for Biden 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, though 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."

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, and there were scattered protests during his speech.

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 "ceasefire now" during Fain's afternoon speech Monday. The union called for a ceasefire 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."

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's making sure to follow union procedures on the endorsement and show that members made the decision, even though there's no way the UAW would have backed 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't 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's administration also supported the union's bid to persuade Stellantis to reopen a shuttered plant in Belvidere, Illinois, and joined Fain in the city 70 miles (113 kilometers) northwest of Chicago to celebrate its reopening, Fain said.

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

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

___

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