America Pac last quarter spent millions on digital communications, mailings and phone calls opposing Talarico, as well as thousands on political marketing to support Paxton.

At the same time, Musk donated another $10m to Lone Star Liberty Pac, a group primarily backing Paxton, records show.

The flow of money highlights a major theme for Musk: Texas.

In recent years, the tech CEO has been moving his business empire – including SpaceX, Tesla and X – to the southern US state after expressing frustration with operating in California.

Texas has offered Musk fewer government regulations and no state personal income tax and no corporate income tax.

Keeping politicians who favour looser government restrictions in charge, as Republicans typically have, could help maintain that environment for Musk.

And his big spending in Texas and in the Texas Senate race seems to point to Musk’s understanding of that, political analyst Cayce Myers told the BBC.

“Republicans have a fundraising advantage this time, but fundraising by itself does not actually guarantee success,” he said.