It's Not Really About Rubio
Salon has a nice piece on the Crist/Rubio match-up. Probably the most interesting point it makes is that the major, perceived dynamic of the race is a false image - the moderate Crist vs the conservative icon Rubio.
In terms of actual actions in their elected positions - Crist as governor and Rubio as speaker - can anyone name a significant number of actions that taken in their respective offices that makes Rubio more conservative than Crist?
You can't. Not really.
Rubio is not the conservative in the race. For an angry, anti-incumbent electorate, it is enough that Rubio is not Crist. That is why when the Crist camp points out that Rubio is absolutely part of the "establishment" as a lobbyist and as a former speaker of the house, it doesn't get any traction. If this were ever about Rubio, he would still be twenty points behind. Instead, it's all about Crist, so Rubio's lead is eighteen points and only getting stronger.
We saw a similar dynamic in Massachusetts, where a moderate, pro-choice Scott Brown became the darling of a conservative, pro-lifers across the country.