> Republicans could continue to deny them a majority by refusing to confirm any VP... <
Very true. And that would be the smart play.
But Republicans are not smart. The Senate almost always confirms presidential nominees, under the theory that the president should have the right to choose who he wants to work with.
So I’ll betcha that at least one GOP senator would fold, and respect that “tradition”.
I don’t think there’s such a “tradition” here. There have only been two appointments of a VP under the 25th Amendment, both Republicans during the same Democrat-controlled Congress. When Agnew resigned, Congress basically dictated to Nixon that he nominate Ford.
When Ford became President and nominated his own successor, he nominated the liberal Nelson Rockefeller, even though his real preference probably would have been Don Rumsfeld or George Bush. Electoral politics are usually cited as the reason, but I suspect confirmation by the Democrat Congress also played a role. Rumsfeld famously blocked Rockefeller out of any real role in the administration anyway.