Billionaire Elon Musk on Sunday handed out million-dollar checks to two voters in Wisconsin and promised smaller payments to others who help elect a conservative candidate to the state’s top court in a closely watched election.

The Tesla CEO, a top adviser to US President Donald Trump, handed out oversized checks at a rally in Green Bay as he sought to drum up enthusiasm for a state Supreme Court election that is already the most expensive judicial race in US history.

Musk said he would also pay supporters $20 for every voter they recruit over the next two days.

He said he was spending the money to raise awareness of a race in which liberal Susan Crawford seems to be running ahead of conservative Brad Schimel.

“We actually are in serious danger of losing the election,” he said. “We’ve got to pull a rabbit out of a hat.”

The April 1 contest will determine the ideological tilt of the state’s top court as it considers abortion rights, labor rights and possibly election rules.

Technically nonpartisan, the race is seen as an early referendum on Trump in a politically competitive state.

Musk warned the court might redraw legislative districts in a way that could cause Trump’s Republicans to lose seats in the US House of Representatives.

“I think this will be important for the future of civilization. It’s that significant,” Musk said.

As of last week, groups affiliated with Musk had spent at least $17.5 million to support Schimel, according to New York University’s Brennan Center for Justice — more than one-fifth of the $81m spent in total on the race.

Musk’s $1m giveaway echoed his tactics from the 2024 presidential election, when he gave checks to voters who signed petitions supporting conservative causes.

Wisconsin’s attorney general, Democrat Josh Kaul, sued to block the giveaway but the state supreme court ruled it could go ahead, according to the Washington Post.

Musk spent more than $250m to help elect Trump last year, far more than any other individual, and his appearance in Wisconsin showed his willingness to get involved in downballot races as well.

Trump has deputised Musk to oversee an unprecedented effort to slash the federal government that has effectively shuttered several agencies and fired tens of thousands of workers.