Nobody sees him as really being a Republican. He’s just seen as a left-leaning opportunist who flip flopped completely when he was taken as too moderate for his own party (the GOP).

He won in 2006 to replace Jeb. He was considered a moderate up-and-comer who’d be palatable to voters, especially in a blue wave year. He attacked Obama through and through in ‘08, then when he won suddenly decided to support his stimulus. Then unpopular US Senator Mel Martínez (R) said he wouldn’t run for re-election in 2010. Crist decided instead of running for his own re-election, he’d run for the Senate seat. Problem was, Marco Rubio was also running, and he decimated Crist’s primary support. So Crist turned independent (and came second to Rubio in a 3 way general). By 2014 he’d become an “Obama Democrat” (despite having previously attacked Obama through and through in ‘08) and won the gubernatorial nomination. A rather unpopular Rick Scott narrowly won re-election. And then in 2016 he won a US house election in a safe Dem seat.