When Marco Rubio announced his candidacy for the open U.S. Senate seat in Florida, he inadvertently launched another battle in the war over the GOP’s march to the center.

Rubio plans to run on staunchly conservative principles, pegging him against Florida Gov. Charlie Crist in the Republican primary. Crist has more moderate temperaments and much higher name recognition. Senate leaders immediately backed Crist when Rubio announced his candidacy, as did the Republican Party of Florida (RPOF).

Some observers say that immediately supporting a more centrist, establishment politician bodes poorly for the GOP’s prospects in Florida and elsewhere. Mario Lopez is president of Hispanic Leadership Fund, which works to expand the GOP’s base.

“It just seems like there are a certain amount of assumptions there, not all of which we agree with,” said Lopez. “It’s not a guarantee that somebody a little more conservative is going to be a loser in Florida. Someone with a positive, clear, articulate message can certainly win.”

In addition to his centrist approach to social issues and overtly liberal environmental policies, Crist endorsed Obama’s stimulus plan, which was supported by only three Republicans in Congress. One of those Republicans, Arlen Specter, has since switched parties.

As Speaker for the Florida House of Representatives, Rubio promoted a strict diet of fiscal responsibility and limited government, and is more conservative on social and cultural issues.

“Whether it's right or wrong for them to have done so, there is a perception that the National Republican Senatorial Committee and the RPOF lining up behind Crist so easily shows that they're not sufficiently interested in pushing young leaders forward and bringing new, diverse talent to the party's front bench on a national level,” said a Republican strategist who is closely following the Senate race in Florida.

Senate leaders said that choosing Crist over Rubio was more pragmatic than ideological.

"It was a choice about who could win," NRSC Chairman John Cornyn (Texas) told Politico, a week after he said that he would take no position in the race. Continued...