Mr. Musk has spent at least $119 million mobilizing Trump supporters in the US presidential election, and his social media platform X has become a source of pro-Trump propaganda. At the same time, Mr. Musk has come under increasing scrutiny, missing a hearing on Thursday in a lawsuit over his attempts to hand out millions of dollars to registered voters in grants that legal experts say amount to buying votes. The Securities Exchange Commission is also understood to be investigating Mr. Musk.