President Joe Biden joined striking workers Tuesday in Michigan just days after United Auto Workers President Shawn Fain publicly challenged him to do so. The appearance — and one planned a day later by former President Donald Trump — come as each candidate scraps for union members’ support in 2024. 

Biden addressed workers through a megaphone outside a General Motors Service Parts Operations plant in Belleville, one location of 38 where workers are striking in response to stalled contract negotiations with the Big Three automakers — GM, Ford and Stellantis.

“The unions built the middle class. That’s a fact,” Biden told them. “Let’s keep going, you deserve what you’ve earned. And you’ve earned a hell of a lot more than you’re getting paid now.”

Although it’s not Biden’s first picket line — White House officials noted that he joined several as a presidential candidate, including a UAW picket in 2019 — Biden is likely the first sitting president to do so in at least the last 100 years or so, ​​according to a FiscalNote analysis of presidential remarks dating back to Herbert Hoover.

“He’s standing with them to make sure that they get a fair share,” White House Press Secretary Karine Jean-Pierre said. “They are at the table, trying to figure out what this agreement is going to look like. They are going to decide the specifics of that agreement,” she added, referring to the UAW.

Biden is notoriously vocal about his pro-worker resume, frequently calling himself the “most pro-union president” and touting made-in-America mandates for infrastructure projects that he says will guarantee good-paying union jobs. Other Democratic lawmakers have also taken to the picket line to show solidarity, including Senate Majority Leader Charles E. Schumer, D-N.Y., who joined striking autoworkers in Rockland County, N.Y., Tuesday morning.

But as automakers make the massive transition to electric vehicles and other zero-emission models — a push incentivized by Biden and Democratic policies like tax credits through the 2022 reconciliation law — Trump and some GOP lawmakers argue that the administration is sacrificing worker pay and quality jobs to reduce emissions.

In a post published on Trump’s campaign website Monday, Trump said Biden has been a “complete disaster” for autoworkers in the U.S., adding that the president is taking jobs away from unions and giving them to China. He also suggested Biden’s visit occurring just a day before Trump’s scheduled trip to Michigan was more about strategy than solidarity with workers.

Trump is slated to deliver remarks at Drake Enterprises, an automotive supplier, in Clinton Township, Mich., on Wednesday night, according to his campaign. The Michigan AFL-CIO confirmed that Drake Enterprises is not unionized.

Fain and Michigan Democrats said Trump was not welcome on the picket line, but Trump said he wished to speak to workers who are being “sold down the river” by their union’s leadership.

A ‘just’ transition

Republican lawmakers like Sens. J.D. Vance of Ohio, Josh Hawley of Missouri and Ted Cruz of Texas have echoed Trump’s concerns, seizing on the strike to renew their criticism of the administration’s EV policies, which includes the goal that half of all new cars sold by the end of the decade will be zero-emission models.

[As Democrats back autoworkers, GOP spots a divide over EVs]

Hawley visited the picket line at a GM plant in Wentzville, Mo., on Monday, emphasizing that workers need a guarantee that their jobs will stay in America.

“These companies are making billions in profits — and spending billions on idiotic ‘climate change’ initiatives that make China rich and kill American jobs,” Hawley wrote on X, formerly known as Twitter. “Spend that money on American workers.”

Amid the battle, Fain hasn’t officially endorsed a candidate for the 2024 presidential election.

Although the UAW has repeatedly rejected the view that EV jobs are implicitly anti-worker, the UAW president has been wary of Biden’s EV transition agenda in the past. Fain said in May that he is holding off on an endorsement because of the president’s electric vehicle policies and other issues, adding that he hoped a strike would force Biden to “pick a side.”

Since then, the UAW has made some gains at electric vehicle facilities. Last month, workers at a joint battery venture between General Motors and LG Energy Solution in Lordstown, Ohio, ratified an interim agreement that immediately raised wages by $3 to $4 an hour. Fain also praised Biden’s support for “strong contracts” for a “just transition” to an EV future in August.

But such a sweeping transition doesn’t come without growing pains, which may translate to uncertainties for its workers.

Ford announced Monday that it is pausing construction on a $3.5 billion EV battery plant in Michigan over concerns about continuing contract negotiations. Fain blasted the automaker, calling it a “shameful, barely-veiled threat by Ford to cut jobs” in a statement. 

“Closing 65 plants over the last 20 years wasn’t enough for the Big Three, now they want to threaten us with closing plants that aren’t even open yet. We are simply asking for a just transition to electric vehicles and Ford is instead doubling down on their race to the bottom,” he said.

It’s not clear if Biden’s visit will be enough to woo Fain’s endorsement.

The union president also continues to blast Trump and has reminded workers that Trump is a part of the “billionaire class” that “enriches people like Donald Trump at the expense of workers.”

In the days leading up to his visit, it seems Trump is pivoting to attempt to court union workers who remain hesitant about the EV transition.

“When [Biden] slowly walks to pretend he is a picket, REMEMBER, HE WANTS TO TAKE YOUR JOBS AWAY AND GIVE THEM TO CHINA,” Trump wrote on his social media platform, Truth Social.

David Jordan contributed to this report.