Sen. John Cornyn (R-TX), the head of the National Republican Senatorial Committee, gave this interesting explanation to Human Events for why his committee has stepped in so early to support moderate Florida Gov. Charlie Crist over his more conservative challenger Marco Rubio:

"Gov. Crist is the strongest candidate that will enable us to hold the seat," Cornyn told me, "Marco Rubio...[has] a bright future ahead of him, but right now the Mason Dixon poll shows Crist beating him in a primary by 53% to 18%." By nominating Crist, Cornyn believes, "we won't have to spend precious resources in Florida" to retain the seat of retiring Sen. Mel Martinez (who has also endorsed Crist).

So it's not just about getting a winning candidate in Florida, but it's also about getting a candidate who can win by a sufficient margin so that the party won't have to spend too much money in a big swing state.

The Democrats have been able to behave effectively in this rational manner for recent cycles -- probably the best example would be the recruitment of Bob Casey in the 2006 Pennsylvania Senate race. So the question here is whether the GOP's current activist base can line up in the same way.