Cornyn ... acknowledged that retiring Sen. Mel Martinez (R-Fla.), ... could resign early.
sources close to Martinez said he might very well exit early and is actively looking for jobs for his post-Senate career. They say that if a great opportunity presented itself that required him to resign early, he would do just that.
"He has been looking for a job, and he has been telling all his friends, for a while, that if the right opportunity came along he would consider leaving before his term was up," said a Florida Republican source.
A GOP aide said plainly: "Mel is going to do what's best for Mel."
At that point, Governor and Senate-candidate Charlie Crist would have an opportunity:
... Crist could use the (replacement appointment) decision to bolster his standing with groups like Cuban-Americans. It's unlikely Crist would resign his post and have the lieutenant governor appoint him to the seat.
If he appoints a caretaker Cuban-American, I don't see how that could backfire.
If Crist self-appointed himself, and ran as the sitting Senator, that could seem tawdry. But more importantly, it would force him to cast actual votes. And everyone would find out: would he fall in line with the minority block, or vote more independently.
And it could also be dependent on just when the opening would happen:
before filing papers are due, or
after that but before the primary, or
after that but before the general election.
And at some point on the calendar he's undoubtedly allowed to just leave it vacant until the next Senator is sworn in (which he's hoping is himself, of course)