CEI’s man in Florida, Cristian Camara, provides the following insightful commentary on Governor Crist’s back-pedaling on global warming and the surprising resignation of Senator Martinez:

Crist has been backpedaling on just about every statist scheme he has embraced as governor. Because Florida is a closed primary state, his embrace of these left-leaning issues is not particularly popular among those whose votes he’s courting in the primary.
I have maintained that Crist is neither liberal, conservative, moderate nor even RINO, as some in his party have labeled him. That would require him to be consistent to a certain level. Instead, he panders to whatever he thinks will score him short-term political points.
As for environmental policy, Governor Crist has pursued aggressive cap and trade policies in Florida, his administration has opposed efforts to build more coal power plants, he has signed several executive orders mandating the use of expensive “renewable” fuels, and has on a personal level hosted and been part of several climate change summits that have attracted the country’s most radical enviromarxists. Now, he’s backpedaling on these and several other issues because there’s a revolt going on within Republican ranks that may spell electoral trouble for him (Rubio, although behind in the polls and fundraising, is beating Crist in straw poll after straw poll, and is able to gather hordes of people at rallies and speaking engagements).
Governor Crist and Senator Martinez are strong political allies. I have no doubt in my mind this early resignation is a move that was agreed to by Crist and Martinez to somehow benefit Crist’s candidacy. Expect Crist’s choice of a replacement to be a carefully calculated move to benefit him. Possibly a Hispanic and/or a strong conservative to shore up his conservative credentials to the base. Some think he may appoint himself, although I think it would spark a Republican civil war in Florida, and I think Crist would want to avoid that, not for the sake of party unity, but because it would hurt his chances at reelection next year.