Larison's thoughts:
The difference between Connecticut in 2006 and Florida now is that there is a serious Democratic contender in the Florida race, so it is not likely that the state’s Democratic voters will be rallying around Crist to deny Rubio the win. It is possible that he will do enough to split the vote with Rubio that Meek ekes out a victory, or Crist might be able to win a three-way race, but either way his political ambitions will never go beyond the Senate now. If he prevents the new Republican folk hero Rubio from winning, he will probably be more hated on the right than Lieberman ever was on the left, and if he delivers a safe Republican seat to the Democrats he can probably forget about running for office in Florida again. Even if Crist pulls off a win this year, his pattern of looking for the next big political job will come to a screeching halt.
Harry Enten gives Crist low odds of winning.