Sometime back Flake decided to do what every young politician does upon realizing he can't be reelected to his current job. He decides to run for a higher office (like President) where a larger group of voters that don't know him might can be confused.
But there is no clear path forward for Flake. There are not enough Bush/Rockefeller Republicans left to get him the GOP nomination.
And the Democrats, who like dishonest liberals like Flake well enough, already have more dishonest liberal politicos than they could elect in 10 lifetimes.
Flakes best hope is that the DNC polling will show the 2020 national ticket needs a proven, weak, impotent white male as the VP candidate.
If he were to become a Democrat, he would find that there are hundreds ahead of him in terms of Presidential seniority.
All Flake has is the Evan McMuffin wing of the party.