From NBC's Chuck Todd and Mark Murray
First Read has confirmed that Florida GOP Sen. Mel Martinez
, who already announced he is not running for re-election in 2010, is resigning from the Senate by the end of the month -- possibly announcing this early as today. It'll be official at some point this month, with the hope of having a replacement in office when the Senate comes back.
Florida Gov. Charlie Crist -- who is already running for Martinez's seats -- will now have to appoint a replacement to fill out the remainder of Martinez's term. The expectation is that Crist WON'T appoint himself, but would rather appoint a placeholder. One rumor is former GOP. Gov. Bob Martinez. Another rumor we've heard is former GOP Sen. Connie Mack.