FLINT, Mich. ― Democratic presidential nominee Kamala Harris on Friday came to the heart of America’s auto industry, promising to stand up for workers whom she said Donald Trump has abandoned.

In a speech to a raucous crowd of several thousand supporters, the vice president touted the Biden administration’s record of investing in the U.S. auto industry and publicly backing its unionized workforce.

“We have brought manufacturing back to America,” Harris said, citing news of newly opened factories in Michigan, which has the nation’s highest proportion of autoworkers and is among a handful of tightly contested states likely to decide the presidential election.

“We know we cannot have a strong middle class without American manufacturing,” Harris said.

But the most pointed and energetic part of Harris’ speech was her sharp attack on Trump, the former president who has made winning Michigan a priority of his bid to get back to the White House.

Harris warned that Trump would undermine the auto industry, citing his history of opposition to organized labor and, more recently, his threats to withdraw support for the production of electric vehicles (EVs).

Harris fights back on EVs.

The reference to EV investments was important because electric vehicles are at the center of a broader debate about the industry’s future.

Democratic policies that President Joe Biden signed into law ― and that Harris has supported ― are subsidizing the production and purchase of electric vehicles while tightening emission standards for new cars and trucks.

The hope is that the combined effect will keep American carmakers competitive with foreign counterparts that are already switching over to EVs while supporting high-paying jobs and helping to reduce emissions that contribute to climate change.

“We want to make sure the next breakthroughs are not only invented but built here in America, by American union workers,” Harris said.

Those subsidies have sparked a massive boom in the construction of EV factories across the South and Upper Midwest in what’s come to be known as the Battery Belt. But whether that’s good for the industry and its workers in the long run is the crux of the dispute in the presidential campaign.

Trump says the subsidies and regulations are forcing the auto industry to make vehicles consumers don’t really want. This “EV mandate,” as he calls it, will lead to financial ruin and a loss of jobs to competitors such as China.

Harris on Friday addressed those arguments directly.

“Contrary to what my opponent is suggesting, I will never tell you what kind of car you have to drive,” Harris said. “Here is what I will do: Invest in communities like Flint, which helped build the auto industry and the [United Auto Workers union]. We will retool existing factories, hire locally and work with unions to create good-paying jobs.”

Harris went on to say that Trump’s refusal to support EV production while he was president is one reason American companies need to catch up now.

“When it came to building the cars of the future, Donald Trump sat on the sidelines and let China dominate,” Harris said.

Harris singles out recent Vance comments.

Harris also took a moment to address recent comments by Republican vice presidential nominee JD Vance, who was in Michigan on Wednesday.

At a pair of appearances, reporters from the Detroit News asked the Ohio senator whether Trump would keep supporting electric vehicle production, including a planned $500 million investment to convert a General Motors plant in Lansing over to EV production.

Vance declined to say yes and proceeded to attack the EV push as a sop to Chinese competitors.

“We ought to be rebuilding the American middle class and investing in our own workers, not shipping our tax dollars off to electric vehicles made in China,” Vance said.

That statement prompted immediate, sharp rebukes from the UAW and top Michigan Democrats, who cited GM promises to use American-sourced materials at the plant and warned that pulling back on support could mean Michigan losing jobs.

Harris in her speech made it clear to voters that she agrees.

“Michigan, we fought together for those jobs, and you deserve a president who won’t put them at risk,” Harris said.

Making the case to Michigan.

Campaign appearances in Michigan from either Trump or Harris ― or Vance or Democratic vice presidential nominee Tim Walz ― are taking place several times a week now.

It’s a sign of how important the state has become politically and how close both campaigns believe it to be.

Polling suggests Harris is slightly ahead right now, but polling underestimated Trump’s Michigan support in 2016, when he won the state.

And though Democrats have performed well in recent elections, including resounding wins in the 2022 midterms that gave the party full control of state government, polling suggests Trump is making inroads nationally with working-class voters, especially white working-class voters, who have outsized influence here.

Trump was actually in the same arena two weeks ago for a town-hall-style appearance. He packed the hall with his supporters, just as Harris did on Friday.

To win back some of those voters, or at least persuade undecideds, Harris and her allies are doing their best to highlight Trump’s support for tax cuts that benefit the wealthy and his ongoing talk of repealing the Affordable Care Act, along with other policies they believe show he has been no friend to the working class.

And to carry this message, Harris is calling on trusted surrogates, such as UAW President Shawn Fain, who appeared at the rally wearing his now-familiar “Trump is a scab” T-shirt, and Gretchen Whitmer, the state’s popular Democratic governor.

“The Trump-Vance ticket is giving the middle finger to workers here in Michigan,” Whitmer said at the rally.

Friday’s rally included one other high-profile advocate: Earvin “Magic” Johnson, who in addition to being one of the greatest professional basketball players in history is also a Michigan native ― and, as he reminded the crowd, the son of a unionized autoworker.

Johnson said he was particularly eager to reach younger Black men, whom surveys have suggested are not supporting Harris by the same large margins with which they have supported Democrats in the past.

“Kamala’s opponent promised a lot of things to the Black community that he did not deliver,” Johnson said, referring to Trump’s time in the White House. “We’ve got to make sure Black men understand that.”