Measured in cheeseburgers, Elon Musk's midterm spending comes to more than 31.9 million of them at the Tesla Diner in Los Angeles. Measured in dollars, it is at least $445.77 million, according to Federal Election Commission data as of 29 October.

That money has flowed into Republican-aligned political action committees and groups since last year, making Musk the party's most prominent financial backer and the biggest single-cycle donor in modern US history. The pattern of the spending is as striking as its size. Only last year, after putting nearly $300 million behind Donald Trump's 2024 presidential campaign, Musk said he would step back from large-scale giving. The filings tell a different story: about $200 million arrived in the final two months of campaigning alone.

His largest single contribution, $216 million, went to his own America Pac, which has targeted 43 House and Senate races with television commercials, digital ads, text messages and mailers. The effort is concentrated rather than evenly spread. America Pac has made 839 independent expenditures in House races and 623 in Senate races across 17 states, with battlegrounds such as Michigan and Arizona receiving more support. Texas, Musk's home state, has absorbed the most.

There, a tight Senate contest between Democrat James Talarico and Republican Ken Paxton has become the most expensive race of the midterms. The scale dwarfs the efforts of well-known megadonors such as George Soros or Michael Bloomberg.