(Bloomberg) -- The United Auto Workers union endorsed Joe Biden’s 2024 reelection bid, with the group’s head calling questions about the 81-year old president’s age “bullsh*t.”

“Joe Biden has earned it,” UAW President Shawn Fain said Wednesday, delivering a long-sought boost to Biden’s campaign ahead of an increasingly likely rematch with Donald Trump.

“Joe Biden bet on the American worker, while Donald Trump blamed the American worker,” Fain added at the group’s annual conference in Washington. 

The endorsement — which the group withheld last year in the lead-up to its strike at Detroit’s Big Three automakers — is a needed lift for a campaign that is banking on union support to carry Biden to reelection in November. The auto workers union is influential in Michigan, a battleground state Biden needs to win.

Fain told reporters Wednesday that they will pour resources into get-out-the-vote efforts in Michigan and other battlegrounds. 

“We’re going to press like hell,” he said. 

Still, Biden will need to court rank-and-file members. White, blue-collar workers form the backbone of Trump’s base. The Republican frontrunner, whose win Tuesday in New Hampshire moved him closer to sewing up the nomination, has sought to make inroads with labor — in part to undermine Biden’s claim he is the most pro-union president in American history. Teamsters union chief Sean O’Brien met with Trump earlier this month as the group weighed its presidential endorsement.

Attacking Trump

Fain laid into Trump, calling him a “scab” and accusing him of wanting “to put the race-to-the—bottom on steroids to screw the American working class.”

“If Donald Trump ever worked in an auto plant, he wouldn’t be a UAW member,” he said, prompting jeers from the crowd. “He’d be a company man trying to squeeze the American worker.”

Following pressure from Fain to back the group’s demands in contract negotiations with General Motors Co., Ford Motor Co. and Stellantis NV, Biden last year became the first modern US president to visit a picket line.

“I was so damn proud to stand in that picket line with you,” Biden told the group. 

Rank-and-File Support 

Muriel Samuels, a retired Flint, Michigan, GM employee said she was confident that Biden, after joining autoworkers on the picket line, would win their votes this year. 

“He’s not sitting up in a White House or somewhere giving a speech – he’s down there on the front lines with us,” Samuels said. 

Holding off from endorsing Biden last year was “a good way to make sure that we have the attention of the White House and their focus on our issues, and to encourage them to work with us,” said David Rogers, a GM employee from Missouri who attended Wednesday’s conference. 

“He was there for us. I see no reason why we won’t be there for him in large numbers,” Rogers added. 

Even in Republican-dominated Tennessee, the vast majority of workers at the glass plant where Rodney Wood works — which makes windshields for the Ford F-150, Escape and several other models — are on board for Biden and other Democrats, Wood said. 

“He walked the picket line with us,” said Wood, the vice president of Local 737 in Nashville. “He’s the first one we’ve had to do that.”

The UAW gathered at an annual conference and made its endorsement decision fresh off one of its most eventful years in recent memory. The union staged a 46-day strike against all three major US automakers simultaneously and gained a 25% wage hike, among other concessions from the companies. 

Read more: Biden Hails UAW Deal With Big Three as Good News for US Economy

Fain, who was greeted with shouts of “UAW! UAW!” when he took the stage Wednesday, has flexed his muscles, setting his sights on organizing non-union plants at 13 companies, including Toyota Motor Corp. and Tesla Inc., led by anti-union Chief Executive Officer Elon Musk.

Read More: Tesla, Trump Are Next Targets for Union Hero After Big UAW Win

--With assistance from Ian Kullgren, Akayla Gardner and Josh Wingrove.

(Adds Fain comment about Michigan get-out-the-vote efforts starting in fifth paragraph)

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