Who: Virginia Gov. Bob McDonnell (R)
The Buzz: McDonnell endorsed Mitt Romney, the only candidate besides Ron Paul to make it on his state's ballot, and Romney said last summer that McDonnell would be on "any candidate's short-list" as a VP pick. Rep. Tim Scott (R-S.C.) has already started referring to McDonnell as "Mr. Vice President."
His Response: McDonnell said on "Meet The Press" in March that he wasn't interested in the position. "I've got the job held by Jefferson and Henry," he said. "I love being governor of Virginia."
Who: New Jersey Gov. Chris Christie (R)
The Buzz: Christie fielded numerous calls to run in 2012, and is now attracting speculation as a possible VP pick by Mitt Romney, who called Christie, "one of the leading figures in the Republican party."
His Response: Christie didn't do much to quell the rumors in December when he addressed them by saying:
I don't think you talk about that stuff. I think if you're the nominee you're afraid to talk about that stuff because you don't want to jinx yourself. I don't think [Romney] wants to be presumptuous enough to start talking to somebody about a vice president when he's not yet the nominee.
Who: Florida Sen. Marco Rubio (R)
The Buzz: Newt Gingrich called Rubio an "awfully good" choice, while Mitt Romney named him as an obvious choice for the short-list.
As the Huffington Post's Carlos Harrison reported, "He's the posterboy for a demographic coveted by the GOP: a telegenic Tea Party favorite and a Latino. And despite being both young and a freshman among Washington, D.C., power brokers, he exerts outsized influence."
His Response: Rubio himself seems less enthusiastic:
When asked at the Washington Ideas Forum at the Newseum in Washington DC, Rubio repeated twice for emphasis, "I am not going to be the Vice Presidential nominee. I am not going to be the Vice Presidential nominee."
Asked during the forum if he would turn down an offer if the Republican presidential nominee asks him to, Rubio responded, "Yea, I believe so," adding again, "the answer is gonna be no."
Who: Nevada Gov. Brian Sandoval (R)
The Buzz: Ahead of the Nevada caucus, Sandoval was speculated to be a potential VP pick:
Nevada's governor Brian Sandoval has been bandied about as a potential -- if longshot -- veep choice since his election in 2010. On paper, his resume looks solid. He's a young rising star in the party with strong approval ratings and, as a Hispanic Republican, could help a Republican nominee -- and especially Romney -- stop the bleeding with one of the party's weakest general election demographics.
While no candidates have floated his name for VP yet, Mitt Romney did mention him as a possible Cabinet member.
His Response: After endorsing Rick Perry last September, Sandoval denied that he was looking for a VP nod. "I am absolutely committed to serving out my term," he said.
Who: South Carolina Gov. Nikki Haley (R)
The Buzz: Haley's endorsement of Mitt Romney didn't do him much good in the state, but her name has still come up as a possible candidate for VP.
Her Response: "I'd say, 'Thank you, but no,'" Haley told ABC News. "I made a promise to the people of this state. And I think that promise matters. And I intend to keep it."
Who: New Mexico Gov. Susana Martinez (R)
The Buzz: Martinez has attracted attention as the first female Hispanic governor, and Mitt Romney mentioned her as a good possible running mate.
Her Response: Martinez has said she's flattered, but not interested:
"She has no interest in serving as vice president and will not be a candidate for the position," Martinez spokesman Scott Darnell said in a statement according to the Santa Fe New Mexican on Friday.
Who: Former Mississippi Gov. Haley Barbour (R)
The Buzz: Barbour was considered a promising candidate for the 2012 nomination until he decided not to run last summer.
Mitt Romney has mentioned Barbour as a name he'd consider for vice president.
His Response: Barbour wouldn't turn down the possibility of being VP, but he said he didn't anticipate being asked.
"I don't think I'm a good running mate for anybody, but I do think Marco Rubio would be very attractive as would other people," he told FOX last November.
Who: Indiana Gov. Mitch Daniels (R)
The Buzz: Daniels hasn't endorsed a candidate yet, but he's considered a potential pick for the VP slot. His book, "Keeping the Republic: Saving America by Trusting Americans," added to the hype.
His Response: Daniels was asked about the possibility last fall:
"There's no answer to this question," Daniels said when the vice president's job came up while he was promoting his book. He said he'd have to consult his family, which earlier vetoed the idea of him running for president.
Who: Arizona Gov. Jan Brewer (R)
The Buzz: Brewer made headlines for a confrontation with President Barack Obama at an airport in Phoenix.
Does Brewer want another chance to take on the Obama administration? The Arizona Republic reports that her name has surfaced as a possible VP candidate.
Her Response: None so far.
Who: Former Minnesota Gov. Tim Pawlenty (R)
The Buzz: Pawlenty was a short-lived presidential candidate, quitting in the summer after a third-place finish in the Iowa straw polls. He later endorsed Mitt Romney, who named him as a possible VP candidate.
His Response: Pawlenty said in an interview that he'd taken himself "off the list" to be considered as Romney's VP.
Who: Sen. Rob Portman (R-Ohio)
The Buzz: Portman is a supporter of Mitt Romney. In December, his home state's Dayton Daily News ran an article touting his chances to become VP:
His deep resume and absence of political negatives keep him in the discussion as a vice-presidential candidate.
"I would be very surprised if the eventual nominee doesn't have Rob on the short list,'' said Tony Fratto, who served as White House press secretary to former President George W. Bush.
His Response: Portman is noncommittal about being on anyone's presidential ticket. "I truly am not seeking that," he said in an interview with the Dayton Daily News' Washington Bureau.
Who: Louisiana Gov. Bobby Jindal (R)
The Buzz: Jindal, who endorsed Rick Perry, has seen his star fade since his widely panned State of the Union response in 2009.
But he is still viewed as a potential pick. Florida Gov. Rick Scott (R) praised him, saying, "He's well-liked. He's a nice person to deal with. He clearly cares about people. He's willing to make tough choices," Scott said. "So I think he would make a great vice president."
His Response: "I don't want a job from Governor Perry," Jindal said after endorsing the former candidate. "I want Governor Perry to create millions of jobs for my fellow Americans."
Who: Sen. Jon Thune (R-S.D.)
The Buzz: Thune, once viewed as a potential 2012 candidate himself, has since endorsed Mitt Romney.
His Response: Thune has said he's not interested in the VP role, but he wouldn't rule anything out.
Who: Sen. Kelly Ayotte (R-N.H.)
The Buzz: Ayotte was an early supporter of Mitt Romney. He gave her an endorsement of his own, naming her as a possible pick for vice president.
Her Response: Ayotte said she was "surprised" by Romney's comment, but that "certainly it was an honor to be mentioned."
"I am very committed to representing New Hampshire," she told the New Hampshire Union Leader. "It is such a privilege to serve New Hampshire in the U.S. Senate."
Who: Kansas Gov. Sam Brownback (R)
The Buzz: Brownback endorsed Rick Perry for president, prompting speculation that he could be looking for a spot as vice president. Brownback also briefly ran for president in 2008.
His Response: During the last election cycle, Brownback said he'd be "honored" to serve as John McCain's vice president. He hasn't yet commented this time around.
Who: Rep. Allen West (R-Fla.)
The Buzz: West has been named as a strong contender by a number of his peers, including Herman Cain, who called him an "excellent choice", and Nikki Haley, who said he would make a "good" pick.
His Response: "Yes, well, right now, you know, the focus is, of course, being a good congressional representative," West told CNN's Kyra Phillips. "But if someone were to make that call to me, which I really doubt is ever going to happen, you would have to make sure that it is something that god would ordain for you, and you'd have to talk to your wife, my wife and my two daughters about. But we have always stepped up to the plate to serve our country. And if it's the right fit, then I will do so."