Marco Rubio officially threw his hat into Florida’s open-seat Senate race Tuesday morning, and while the former state Speaker is the frontrunner among announced GOP candidates, that will certainly change if, as is expected, Gov. Charlie Crist joins the race.While Crist has indicated he will wait until the end of the state’s legislative session before announcing his plans for 2010, GOP officials, including retiring Sen. Mel Martinez, have said there’s a strong likelihood that the governor will join the race. And that prospect has made Republicans on Capitol Hill and in Florida downright giddy.“Nobody could touch [Crist] for the Republican nomination,— Rep. John Mica (R-Fla.) said last week. Asked how the Florida Republican delegation might fall out in a contested GOP primary race, Mica said, “I think the delegation is seasoned enough to recognize a winner.—Rep. Bill Young (R-Fla.) conceded that the race isn’t a slam dunk, even though Crist’s popularity has led some prognosticators to predict he might be able to waltz into the Senate seat.“I don’t think anything’s going to be easy,— Young said. But “I think Charlie’s very popular in Florida and I have no trouble voting for him.—After forming his exploratory committee five months ago, Rubio recently made it clear that he has no plans to exit the primary even if Crist enters the race.On Tuesday, Rubio — who is known as a social conservative who backed former Arkansas Gov. Mike Huckabee in the 2008 Republican presidential primary — said in a statement that he wanted to serve in the Senate because he believes the country is at “a proverbial crossroads— and that America’s future depends on which path is followed.“This campaign isn’t going to be a campaign against anyone, nor will it be a campaign against anything,— Rubio said. “This is a campaign for the kind of ideas that will change our country for the better, a campaign for ideas like tax reform — tax cuts alone are not enough.—