Flake is also one of the rare politicians whose brand changed dramatically. In the 2000s, he was a Jim DeMint ally who took a strong libertarian stand on several issues, and criticized the George W. Bush administration from that perspective. In the Senate, his brand shifted significantly – and not just because of the Gang of Eight. The list of fights he joined in the House was long – it’s hard to remember what major fight he chose to advance in the Senate. In response to his speech on the floor today, Mitch McConnell said “We’ve just witnessed a speech from a very fine man,” and called him a “team player”. Exactly – Flake left his populism behind, and became less a part of the internal critics of McConnell and his style of governing the body (despite the fact that if such methods had changed, Flake might not be in the predicament he is now).

In a sense Flake had the worst of both worlds – he was a McConnell team player who voted very much in line with Donald Trump and the GOP agenda, while also being one of the president’s most prominent public critics. Stepping down makes it much more likely that someone will jump into the primary against Kelli Ward who has the potential to win the seat (keep an eye on Rep. Martha McSally in particular), and is thus different than the calculation on Bob Corker’s part. This decision is Flake recognizing reality has shifted, but it is also about recognizing that he – just like Corker and others who will likely bail – is incapable of making anything happen. This is less a changing of the guard, because Flake is not the guard, he’s more of a bystander to the guard, and he knows it.