WASHINGTON – President Joe Biden forcefully sided with the striking United Auto Workers (UAW) on Friday, dispatching two of his top aides to Detroit and calling for the three biggest American car companies to share their profits with employees whose wages and benefits he said have been unfairly eroded for years.

In brief remarks from the White House hours after the union began what it called a targeted strike, Mr Biden acknowledged that the auto makers had made “significant offers” during contract negotiations, but he left no doubt his intention to make good on a 2020 promise to always have the backs of unions.

“Over generations, auto workers sacrificed so much to keep the industry alive and strong, especially the economic crisis and the pandemic,” Mr Biden said. “Workers deserve a fair share of the benefits they helped create.”

Mr Biden said that Ms Julie Su, the acting secretary of labour, and Mr Gene Sperling, a top White House economic adviser, would go to Michigan immediately to try to bring both sides back to the bargaining table.

But he said the auto makers “should go further to ensure record corporate profits mean record contracts for the UAW”.

For decades, Mr Biden has been an unapologetic backer of unions who rejects even the approach of some Democrats when it comes to balancing the interests of corporate America and the labour movement.

During the past several years, he has helped nurture what polls suggest is a resurgence of support for unions, as younger Americans in new-economy jobs push for the right to organise at the workplace.

Mr Biden declares that “unions built the middle class” in virtually every speech he delivers.

“That was most pro-union statement from a White House in decades, if not longer,” Mr Eddie Vale, a veteran Democratic strategist who worked for years at the American Federation of Labour and Congress of Industrial Organizations (AFL-CIO), said after the president’s remarks.

The president’s decision to weigh in on the side of the union without much reservation will most likely to draw fierce criticism from different quarters.

Earlier in the day – even before the president’s White House comments – Ms Suzanne P. Clark, the head of the US Chamber of Commerce, issued a searing statement blaming the strike on Mr Biden for “promoting unionization at all costs”.

After Mr Biden’s remarks, Mr Neil Bradley, the group’s top lobbyist in Washington, said the president’s message and the pro-union policies his administration has pursued have “emboldened these demands that just aren’t grounded in reality”.

And in a possible preview of a rematch with former president Donald Trump, NBC on Friday aired part of an interview in which Trump sided just as forcefully with the car companies against the unions.

“The auto workers will not have any jobs, Kristen, because all of these cars are going to be made in China,” Trump said in an interview set to air Sunday on the network’s “Meet the Press” programme. “The auto workers are being sold down the river by their leadership, and their leadership should endorse Trump.”

Friday’s walkout by the UAW is in some ways a broader test of Mr Biden’s economic agenda, beyond just his pro-union stand.

It also touches on his call for higher wages for the middle class; his climate-driven push to re-imagine an electric vehicle future for car companies; and his call for higher taxes for the wealthy. The strike is centered in Michigan, a state that the president practically must win in 2024 to remain in the Oval Office.

“You’ve got rebuilding the middle class and building things again here,” Mr Vale said. “You’ve got green energy, technology and jobs. You’ve got important states for the election. So all of these are sort of together here in a swirl.”

At the White House, Mr Biden’s aides believe the battle between the car companies and their workers will underscore many of the president’s arguments about the need to reduce income inequality, the benefits of empowered employees, and the surge in profits for companies like the auto makers that makes them able to afford paying higher wages.

That approach is at the heart of the economic argument Mr Biden and his campaign team are preparing to make in the year ahead. But it sometimes comes into conflict with the president’s other priorities, including a shift toward electric vehicles.

Mr Biden’s push for automobiles powered by batteries instead of combustion engines is seen by many unions as a threat to the workers who have toiled for decades to build cars that run on gas. The unions want factories that make electric cars – most of which are not unionized – to see higher wages and benefits too.

So far, Mr Biden has sidestepped the question of whether his push for a green auto industry will hasten the demise of the unions. But Friday’s remarks are an indication that he remains as committed as ever to the political organisations that have been at the centre of his governing coalition for years.

In his remarks Friday, he hinted at the tension inherent in the technological transition from one mode of propulsion to another.

“I believe that transition should be fair, and a win-win for auto workers and auto companies,” he said.

But he added: “I also believe the contract agreement must lead to a vibrant ‘Made in America’ future that promotes good, strong middle-class jobs that workers can raise a family on, where the UAW remains at the heart of our economy, and where the Big Three companies continue to lead in innovation, excellence, quality and leadership.”

Unlike previous strikes involving rail workers or air traffic controllers, Mr Biden has no special legal authority to intervene. Still, he is not exactly just an observer either.

Just before the strike vote, Mr Biden called Mr Shawn Fain, the president of the UAW, as well as top executives of the car companies. Aides said the president told the parties to ensure that workers get a fair contract, and he urged both sides to stay at the negotiating table.

Economists say a lengthy strike, if it goes on for weeks or even months, could be a blow to the US economy, especially in the middle of the country. NYTIMES