Sen. Marco Rubio (R-Fla.) endorsed Mitt Romney for president on Wednesday, becoming the latest big-name Republican to throw his support behind the likely Republican nominee.

Senator Marco Rubio (R-Fla.) (MANDEL NGAN/AFP/GETTY IMAGES)

“It’s increasingly clear that Mitt Romney’s gonna be the Republican nominee,” Rubio said. “We’ve got to come together behind who I think has earned this nomination and that’s Mitt Romney.”

Rubio added: “I have zero doubt in my mind of two things: No. 1, that Mitt Romney will govern as a conservative, and No. 2, that he will be head and shoulders better than the guy who’s in the White House now.”

Romney tweeted following Rubio’s appearance: “Ann joins me in thanking @MarcoRubio for the confidence he is placing in my leadership and for the great honor he has done me today.”

While Rubio didn’t endorse Romney before Florida’s primary, he did give the former Massachusetts governor a boost by criticizing a Newt Gingrich ad that cast Romney as “anti-immigrant.”

Rubio, the son of Cuban immigrants, follows closely on the heels of another big-name Florida Republican, former governor Jeb Bush, in backing Romney. Bush endorsed Romney last week.

View Photo Gallery: There is nothing — literally, nothing — that the Fix loves more in politics than the speculation surrounding whom a presidential candidate will pick as his vice presidential running mate.

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