When Jeff Sessions vacated his seat due to becoming Trump's AG, Trump backed Strange for the Senate bid, and Strange lost to Roy Moore. That's how we ended up with Doug Jones -- arguably the most palatable senator to most people given his fairly middle-ground stance -- in the Senate. Of course, he lost his re-election to a football coach that doesn't know the three branches of government.
Some of the talk that I've seen around here is who will Trump back now in the race. The likely suspect is Katie Britt. Back when the campaigning first started, she seemed like a decent pick for "she probably won't do too much damage" (Democrats in Alabama don't get much of an option). However, from what I've heard, she's been a bit more aligned with the Q mentality, so... probably not so great there.