Surprising almost no one, Florida Governor Charlie Crist announced that he will run for the Senate seat vacated by Mel Martinez.

This is good news and bad news for Democrats.  On the one hand, the Senate seat moves from "tossup" to "leans Republican."  The only reason it doesn't move further is that Crist will face a legitimate primary challenge from the right, from telegenic state House speaker Marco Rubio.  Assuming Crist survives the primary -- no sure thing in today's GOP -- it is difficult to imagine him losing to any of the Democrats currently in the race.

The good news is that it opens up the Governor's mansion at what is probably the worst conceivable time for Republicans.  Redistricting is just around the corner, and GOP loss of either statehouse is highly unlikely.  But the Governor's race is likely now a tossup.  and if the GOP loses the Governor's race it will not control redistricting (which presently favors the GOP strongly), which may threaten GOP statehouse control in the long run.

It is also a bit of a curious move for Crist, who has been thought to harbor national ambitions.  Far better to launch a national career as a two-term Governor of our nation's third-largest state than as a junior member of the Senate (pace Barack Obama).