Disputes among Republicans about parts of Trump's major tax bill threaten approval in the Senate and past compromises reached by the GOP-led House.

The GOP's contentious budget bill narrowly passed in the House, faces dissent in the Senate and has drawn the ire of Elon Musk in a big way.

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.