Their battle comes at a moment when Mr. Trump is engaged in a delicate dance on Capitol Hill to get his signature legislation, the so-called One Big Beautiful Bill, passed through Congress. At the same time, he is trying to negotiate the end to foreign conflicts that are proving much more intractable than he predicted.

Chris Hayes says there's a civil war brewing in the Republican Party, as Elon Musk continues his public crusade against Trump's spending bill.