Green Bay, United States — The world's richest man took to the stage in the US state of Wisconsin on Sunday in a bid to swing the local supreme court to the right, with the help of two $1 million checks for voters.

Elon Musk, the owner of Tesla and SpaceX and an advisor to US President Donald Trump, deployed his largesse along with his rhetoric to try to turn out the vote on Tuesday in favor of a conservative judge.

Wisconsin is a swing state, in the balance between the Democratic and Republican parties, and Musk argued that only a supreme court leaning to the right could protect pro-Trump districts from gerrymandering and voter fraud.

"What's happening on Tuesday is a vote for which party controls the US House of Representatives," Musk declared, arguing that the federal congress was so evenly balanced Wisconsin's seats could decide its majority.

"And whichever party controls the House ... to a significant degree, controls the country, which then steers the course of Western civilization," said Musk, who arrived wearing the "cheese head" wedge hat favored by local football fans.  

"So it's like, I feel like this is one of those things that may not seem that it's going to affect the entire destiny of humanity, but I think it will."

To back up this ambition, Musk has piled some of his own money into the Wisconsin Supreme Court vote.

The race pits conservative Brad Schimel against liberal Susan Crawford. The outgoing judge was backed by Democrats, so a Schimel win would tilt the court right, while Crawford would preserve its liberal leanings.

Wisconsin was won by Trump in the 2024 presidential election, but its electoral districts could be redrawn before the next mid-term Congressional elections in November next year. 

The liberal candidate, 60-year-old Crawford, was campaigning Sunday the old-fashioned way, addressing a crowd at an antiques shop meeting on a rainy morning.

"So Elon Musk, folks, that guy, right? He has now spent more than $25 million, it goes up every day," Crawford told the crowd. "He's working as the unelected right-hand man to the president. He's got an agenda."

Straight-armed salute

There was an enthusiastic crowd at Musk's Green Bay rally but, at small-town meetings, the South African-born oligarch's eruption into Wisconsin's affairs seems to have provoked as much resistance as support. 

Rob Patterson, a 65-year-old retired electrical engineer, came to a rally in Crawford with a sign showing Musk giving a straight-armed salute. 

"Oi wanker, our Supreme Court is not for sale," the sign read.

Since buying himself a $277 million role in Trump's presidential campaign last year, Musk has gained unprecedented un-elected power.

Once Trump returned to the White House he invited his sponsor to head a new cost-cutting agency named after an internet meme: the Department of Government Efficiency, or DOGE. 

In just a few weeks Musk has already sacked or suspended tens of thousands of federal workers, gutted foreign aid and begun the job of dismantling several agencies. 

"It's like a bull in a china shop. He has no idea what he's doing," complained Patterson.

Outside a supermarket in Elkhorn, 70-year-old retired elementary school teacher Linda Suskey says she plans to vote for Crawford to keep balance in the court.

And she doesn't have much time for Musk's blandishments.

"He uses his money to get what he wants, which is more money," she told AFP.

"I think he's got too much power, and he doesn't answer to anybody -- and yeah, he's just controlling things to help the rich get richer."

'Activist judges'

Aside from campaign donations to the conservative, Musk handed two prize checks of $1 million each.

This mirrored his scheme during the presidential race to hand out $1 million a day to a voter who registered in a swing state vital to Trump's victory.

Through his political organization, Musk has also offered $100 each to voters who sign his petition against "activist judges" in Wisconsin.

When he launched the petition, Crawford accused him of seeking to buy a seat on the state supreme court in order to swing judgements in favor of his companies.

Tesla has launched a legal challenge to Wisconsin's law banning car automakers from directly owning car dealerships. The case could well end up before the court.