On the trail, James Talarico, the Democratic Senate nominee, has increasingly gone after Mr. Musk, a critic of his who has given big to a group aligned with the Republican candidate, Ken Paxton.
The 44th president sharply criticized Mr. Trump, who hit back later in the day. Mr. Obama also assailed Vivek Ramaswamy, the Republican nominee for governor of Ohio.
The Democratic presidential primary race appears to be wide open, while JD Vance and Marco Rubio led among Republican voters, a New York Times/Siena survey found.
Democrats are increasingly optimistic about the midterms. But they are being outspent by Republicans. And they are trying to compete in states that favored President Trump by large margins.
No obvious legal authority supports a pre-emptive effort to block the certification of Alaskaβs Senate election if the Republican incumbent narrowly loses.