Flake was one of the most vulnerable Republican senators up for reelection next year. A vocal critic of President Donald Trump throughout and since the 2016 campaign, Flake said it became clear that that opposition would make it impossible for him to get through a Republican primary.
Flake was one of Trump’s favorite targets. Now it’s going to be easier for Democrats to exploit these gaps in incumbents. If Republicans win, it will be Trump’s party going forward.