Sen. Marco Rubio (R-Fla.) (AP)

DELRAY BEACH, Fla. — Sen. Marco Rubio (R-Fla.) isn’t on the ballot this year, but he’s still spending a significant amount of time on the campaign trail.

The popular junior senator is campaigning across the country for Mitt Romney and appeared on the three big Sunday talk shows two days ago to spar with Democrats. He’s also campaigning for gubernatorial candidates in New Hampshire, an attorney general candidate in Missouri and for congressional candidates in North Carolina, according to aides.

Rubio is happy to help where he can, those aides said, but you can’t help but notice that most of his campaigning is occurring outside Florida. And with good reason: Most of Florida’s GOP candidates with ties to Rubio are struggling to pull ahead this year.

First there’s Rubio’s longtime friend and former housemate, Rep. David Rivera (R-Fla.), who’s trailing his Democratic opponent amid federal investigations into questionable campaign tactics. Rubio and Rivera still own a home together in Tallahassee that they  lived in when they served in the Florida House of Representatives. Rubio has described Rivera as a friend whom he’s known since before he ran for political office, but the senator seems to have been avoiding Rivera since hosting a D.C. fundraiser for him last spring.

“I don’t know anything other than what I’ve read in the press. Obviously he’s a friend, we always wish him the best,” Rubio said in response to questions about Rivera earlier this month.

Rivera was notably absent from recent South Florida campaign events for Romney, Rep. Paul Ryan (R-Wis.) and the U.S. Senate campaign of Rep. Connie Mack (R-Fla.). When asked Saturday whether he’s been asked to stay away from such events, Rivera said “I’ve never had a conversation about it.”

Rubio “has done a great job of serving his constituents all over the state and I think also pushing for the policies that I think most Floridians want to see pushed in Washington, including fiscal responsibility,” Rivera said.

Beyond Rivera, there are few liabilities to appearing alongside other Sunshine State Republicans. Rubio co-hosted a fundraiser Monday for Republican Adam Hasner, who served as House majority leader when Rubio was Florida House speaker. But Hasner is trailing Democrat Lois Frankel in the 22nd Congressional District, an area that encompasses West Palm Beach.

“I’m proud of Marco’s leadership in the Senate as a freshman,” Hasner said in an interview. “He’s come in there with a very clear voice on American leadership and on tackling the tough problems that we face. I think he’s one of the most articulate in our party of being able to deliver a message about how opportunity is available for all if we get American back on the right track.”

Then there’s Mack, who — you guessed it — served in Tallahassee with Rubio, but lags behind Sen. Bill Nelson (D-Fla.) with just two weeks remaining.

Beyond Rivera, Hasner and Mack, other Florida Republicans with ties to Rubio are faring well: Reps. Gus Bilirakis (R-Fla.), Dennis Ross (R-Fla.), Ileana Ros-Lehtinen (R-Fla.) and Mario Diaz-Balart (R-Fla.) are all cruising to victory — and then there’s Romney, who supporters believe is poised to win Florida on his way to the White House.

But who can blame Rubio for spending less time in Florida? Considering his national ambitions and rock-solid popularity at home, a Romney victory and wins in all the other races he helped across the country could provide  him greater political rewards than a string of losses among friends and colleagues back home.

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