Sink is the only Democrat to win a constitutional office in Florida this century, so I don't see her as a bad candidate. Besides, I read that the DCCC wants her to run again and they don't usually want poor candidates to run again.
The "best" candidate doesn't mean they are a lock. 'She ain't goin nowhere!
She has a chance because Crist will be running as a team with her and she has the womens' vote and he has the senior vote. Crist is in a tough battle with Scott, they need each other. Hopefully, Pelosi convinces her to run again. She will have the school teacher crowd.