Joining the herd of party leaders, House Minority Whip Eric Cantor endorsed Marco Rubio this morning while slamming Charlie Crist for considering an independent candidacy.

"He is firm in his principles and his beliefs, and he keeps his word," Cantor said on a conference call this morning. "That's the kind of leader that we need in the United States Senate."

Cantor said there were "warning signs" with Crist, specifically his decision last year to stand with President Obama in support of the stimulus bill.

"That caused a lot of us some concern," Cantor said. He alluded as well to last week's veto of a GOP-favored education bill. "Now we hear reports all about perhaps that the governor will seek an independent bid to run against Marco. And that to me shows that someone who has built a career based on our party and the principles that we stand for is ready to jettison that connection in order to stay in office. And I just think that right now we need an entirely different kind of leadership, a principled leadership, and an individual that will keep his word to the voters."

Rubio, meanwhile, downplayed the impact of Crist's potential move.

"I wanted the next U.S. Senator from Florida to be someone that I could trust to go to Washington, stand up to the Obama agenda and offer a clear alternative. Irrespective of what decisions other people make about this race, I still feel like I'm the only candidate in this race who's going to do that," he said. "I want to make sure that all this activity that's going on with regard to the process of politics doesn't distract us from what's gotten to this point and that is our focus on public policy."

Rubio has been endorsed just in the past two weeks by Mitt Romney and Rudy Giuliani as Crist has appeared more inclined to abandon the GOP primary. Cantor joins other members of the GOP leadership who've backed Rubio -- Rep. Paul Ryan (R-WI), Conference Chairman Mike Pence (R-IN) and Study Committee Chairman Tom Price (R-GA).