The nation's largest Tea Party political action committee is backing Florida Sen. Marco Rubio as Mitt Romney's running mate just as Ohio's Rob Portman, considered the frontrunner by many insiders, said he prefers to stay in the Senate Wednesday.

In a poll of Tea Party Express supporters, Rubio was the top pick followed by Wisconsin Rep. Paul Ryan, author of the tough House spending bill, Rep. Allen West, the sharp-tongued African-American lawmaker, Rick Santorum and Sarah Palin. Portman wasn't even on the Tea Party Express list.

"It is not a surprise that Marco Rubio is the favorite," said Tea Party Express Chairman Amy Kremer. She released the poll under the headline "Senator Marco Rubio--Tea Party Choice for Vice President."

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The results came as Portman was being interviewed on WTVN of Columbus, Ohio. He told morning host Joel Riley, "I am happy where I am, I'm fortunate to get to represent our state, and I was elected in 2010 because of my interest in trying to help move our country forward and our state forward here in the U.S. Senate, so that's where I intend to stay."

In appearing to bow out of contention, he did give an endorsement of sorts to former Minnesota Gov. Tim Pawlenty. "I like Pawlenty a lot, I know him pretty well, in fact I've been with him in Ohio," said Portman, who also named Rubio, South Dakota Sen. John Thune and New Hampshire Sen. Kelly Ayotte as strong candidates.

Of course, most of those considered on Romney's short list have been suggesting that they don't want the job. It's considered bad form to publicly campaign for the job.

Romney, meanwhile, has been meeting with pro-life leaders to assure them that he will be picking a pro-life and conservative to be his running mate.