One cause of “wave elections” is when the majority party clearly sees that it is going to lose, the incumbents near retirement exit early because they don’t want to spend the last two to six years of their career in the minority.

https://rollcall.com/2026/03/04/sen-steve-daines-announces-surprise-retirement/

Sen. Steve Daines announces surprise retirement

Montana Republican Steve Daines withdrew his Senate reelection paperwork Wednesday minutes before the deadline.

Roll Call
@Cdespinosa Cause? Or harbinger?
@integerpoet @Cdespinosa ..both? The pessimism of the older, retiring incumbents becomes a self-fulfilling prophecy: they would have been heavily favored to win—their party replacement instead faces long odds.
@Cdespinosa that probably explains WHY he is bailing on re-election, but the timing is the really shitty part of this, because he dropped out so late that no one other than his preferred successor would be able to enter the race