Gentlemen, start your engines.

The 2024 general election took an (unofficial) green flag this week near Detroit, the Motor City, as President Joe Biden and Donald Trump raced to court independent, blue-collar workers in the key swing state.

Seven 2024 Republican primary candidates debated more than 2,000 miles away in California on Wednesday night, but it felt like a consolation race for third place and the prize of — maybe — a Cabinet post in a second Trump administration. The main event of the next election cycle was playing out in Michigan as Biden and Trump delivered the same underlying message to independent voters in very different ways: You deserve more money from your wealthy corporate bosses.

The Democratic and Republican front-runners zoomed to the Wolverine State to deliver a populist message in another presidential race shaping up to be decided based on kitchen table issues and social issues like abortion. Trump used remarks at a non-unionized auto parts factory to play the role of the loud and earth-rumbling stock car. Biden’s much briefer appearance at a United Auto Workers picket line set himself up as an IndyCar, a sleeker machine with a smoother-sounding engine.

Biden and his White House aides tried keeping their line around the 2024 campaign’s first track tight, running close to the political wall in a tricky manner. Team Biden tried to drive on a messaging tightrope by saying the president who has been called “Union Joe” supports the workers but has no opinion about their contract demands. Trump worries not about such things.

“I side with autoworkers of America and with those who want to make America great again, and I always will,” Trump said. “The workers of America are getting — I’m going to put it very nicely — screwed.

“You’re getting screwed,” he added.

One hallmark of this earliest of (unofficial) general election starts has been the 77-year-old Trump painting the 80-year-old Biden as too old and too senile.

“Yesterday, Joe Biden posed for photos at the picket line. But it is his policies that sent Michigan autoworkers to the unemployment line,” Trump said. “He only came after I announced that I would be here. He announced quite a bit later, spoke for a few seconds. … And he had absolutely no idea what he was saying. He didn’t know where he was. He didn’t know what he was saying. ‘Where am I? Where am I?’ he’s saying. ‘Oh, you’re in Michigan.’”

Trump was correct that Biden delivered only brief remarks to striking union workers. But Biden seemed to fully know the score as he spoke through a bullhorn.

“Wall Street didn’t build the country, the middle class built the country. Unions built the middle class. That’s fact,” Biden said. “So let’s keep going. You’ve deserved what you’ve earned, and you’ve earned a hell of a lot more than you’re getting paid now.”

‘Union Joe’

The president known — among his many nicknames — as “Union Joe” appeared to make clear he wants American automakers to give UAW workers the deal they are seeking. But his remarks in Michigan did not square neatly with those of his top aides.

White House Press Secretary Karine Jean-Pierre was asked Monday about what signal should be taken from Biden’s visit to the picket line with strikers on Tuesday.

Jean-Pierre replied that “me saying that the president supports the autoworkers, that’s not anything new. When we’re talking about a president who is … the most pro-union president in history.”

Reporters asked repeatedly why it would be a stretch to believe “Union Joe” would not also support workers’ contract demands. Jean-Pierre replied: “We’re not going to litigate the specifics of the negotiations.”

But that did not square neatly with the visual of Biden standing with red-clad union members as UAW President Shawn Fain declared that “we have the power” because “we do the heavy lifting” — not corporate executives. Nor did the president’s plea to the workers to continue their strike.

Biden is running competitive with Trump in just about every national poll of a possible 2024 general election rematch, so he just might drive his reelection car to victory lane. But, once again, this week showed how the messaging system on his hot rod tends to sputter.

Another example came when a USA Today reporter traveling with Biden on Tuesday evening filed a dispatch to the White House press corps from a fundraiser in California with this nugget: “Biden joked that he wanted to climb on the large tree growing in the middle of the courtyard and said he didn’t want to go home.”

On one hand, Washington is in full meltdown mode with a government shutdown likely to start at 12:01 a.m. Sunday — so who could really blame him? On the other, the report provides more fodder for Trump and his GOP allies to paint Biden as in full cognitive decline.

Then there’s Trump. His usually meandering political rally remarks seem even more so these days amid his mounting legal woes, the latest of which is a civil decision that could wreck his business empire.

At one point Wednesday evening, in the same breath and seemingly in the same sentence, the former president lamented the “mutilation” of trans children and lambasted how much it costs to fill up the gas tank in a Chevrolet Silverado pickup truck.

As the (unofficial) general election heads toward the first turn, polls show voters would rather both front-runners head to the political garage — and retirement from the ultimate race. But neither is showing signs of bowing out, and both clearly realize states like Michigan, where independent voters still move the needle, will likely be the key to victory.

‘Have to endorse Trump’

That is especially true for Trump’s political fate, with Biden also hoping the four-time indicted GOP leader’s likely appearance on the ballot will again drive up the number of votes cast from key Democratic voting blocs like women and Black voters.

Trump’s fate, in many ways, will — again — hinge on how independent voters in four or six swing states feel about their financial security. If the former president can hammer home a message that independent voters had more cash in their pockets and value in their investment accounts during his term, while also convincing them the 91 felony counts he faces are unfair or not all that serious, he could defeat Biden.

An NBC News poll released this week found 37 percent of voters approve of Biden’s handling of the economy. The same survey also recorded the incumbent’s highest overall job disapproval rating of his term, at 56 percent (with 41 percent approving). He also is underwater with the same independent voters he and Trump were courting this week, at 36 percent approval, according to the NBC poll.

When asked if they are satisfied with the state of the economy, 28 percent said yes. That is down from 48 percent in April 2021, just a few months after Biden took office.

Biden and White House officials have said they are aware of but not worried about his low poll numbers.

“Polls are polls,” Jean-Pierre said this week. “They don’t tell the whole story.”

So far, voters are not impressed with the one Biden and Co. are telling. As for Trump, a YouGov poll released Wednesday painted a bleak picture of most voters’ views about him.

The survey shows Trump is underwater by 13 percentage points on the likability scale with voters, and more (47 percent yes to 22 percent no) believe, as a New York judge ruled this week, he inflated the values of his properties. What’s more, among independent voters, Trump trails Biden (37 percent to 40 percent).

It’s going to be a long race.

At one point Wednesday, Trump said the UAW workers walking picket lines are wasting their time because Biden’s electric vehicle policies would end the U.S. auto sector in just one or two years. He urged any unionized workers in the crowd to tell their “guys” to publicly back his candidacy. “They have to endorse Trump,” he said, “because if they don’t, they are just committing suicide.”

Vroom. Vroom.

Editor-at-Large John T. Bennett, a former White House correspondent, writes a weekly column for Roll Call, parts of which often first appear in the subscription-based CQ Senate newsletter.