Who's still in the running to be Romney's running mate?

Sen. Rob Portman, Sen. Marco Rubio, Gov. Chris Christie and Rep. Paul Ryan
AP Photo
Sen. Rob Portman, Sen. Marco Rubio, Gov. Chris Christie and Rep. Paul Ryan
AP Photo

(CBS News) For weeks, Mitt Romney refused to say who was in consideration for the vice presidential slot -- until others tried to say who was out.

The presumptive Republican presidential nominee felt compelled to comment on the process this week after ABC News and the Washington Post reported that Florida Sen. Marco Rubio was not in contention. "Marco Rubio is being thoroughly vetted as part of our process," Romney said.

Romney's remarks may say more about the vetting process itself than whether Rubio is really on the candidate's shortlist. Romney may not reveal his running mate until the Republican convention in late August, but there have been signs on the campaign trail to suggest who may or may not be in contention.

Some possible VP picks -- including Rubio -- are keeping mum on whether the Romney campaign is actually vetting them.

"I've made a decision a long time ago not to discuss the process," Rubio told CBS This Morning co-anchor Charlie Rose on Wednesday. "That's not going to change today. I respect the process that Governor Romney's going through. I'm pretty confident he's going to make an excellent choice. I think those of us involved in politics and supportive of him should give him the space to do that that."

Sources tell CBS News Chief Political Correspondent Jan Crawford that Rubio is unlikely to be Romney's choice in the end. Crawford reports that, according to the Romney campaign, Rubio is a long-shot as a first-term U.S. senator and that Ohio Sen. Rob Portman or former Minnesota Gov. Tim Pawlenty would be more likely choices.

According to CBS News political consultant Scott Conroy, there is an obvious political benefit for Romney to keep Rubio's name in the mix publicly for as long as possible. "It's telling that he went out of his way to comment on this to reporters after for months insisting that he would not say a word about the vetting process," Conroy said. "If he truly was considering Rubio seriously, why not just let the ABC story be incorrect and surprise us all later?"

Conroy explained the strategic benefit of keeping Rubio's name out there: "Many of the conservative activists who love Rubio but are lukewarm about Romney are donating to Rubio-led fundraisers," he said. They are "giving their time and energy to the campaign right now under the assumption that Rubio is indeed being vetted."

Pawlenty, who dropped his own presidential bid early on in the GOP primary process, is a strong contender for a number of reasons that Politico lays out: His working-class upbringing and low-maintenance style have made him a strong surrogate, and his evangelical Christian faith is a bonus.

South Dakota Sen. John Thune recently refused to comment about whether he's being vetted. "There's a process. We don't talk about the process," told USA Today. But his refusal to talk may indicate that he is under consideration -- last month he said he wasn't being vetted.

New Hampshire Sen. Kelly Ayotte, meanwhile, recently told the Daily Caller that the Romney campaign hasn't contacted her about possibly serving as a running mate. "I know that he'll pick who he thinks is the best person... my focus is serving New Hampshire," she said.

Still, Ayotte later joined Romney on the campaign trail and continues to actively campaign for him.

Romney also campaigned recently with Rob Portman. Like Thune, he's keeping quiet about whether he's being vetted.

Many Ohioans who attended the Romney rallies where Portman appeared were excited at the prospect of seeing their senator on the ticket. However, Portman stuck to bland assurances that he's likely to stay in the Senate. "I'm lucky to be where I am," he told one man in the pancake line in Brunswick.

While his potential spot on the 2012 ticket may excite some Ohians, it probably wouldn't thrill many others -- a recent USA Today/ Gallup poll showed that 62 percent of Americans had never heard of him.

Wisconsin Rep. Paul Ryan, as the author of the GOP congressional budget, may be more well known, but he apparently doesn't want to be known as a potential vice presidential pick: When National Journal asked about his vice presidential prospects at the beginning of June, he literally turned on his heel and jogged in the other direction, saying he had to go vote.

Indiana Gov. Mitch Daniels -- who has been more adamant than most that he's not interested in the job -- appears to be out of the running for good, now that he's reportedly slated to serve as Purdue University's next president.

Meanwhile, New Jersey Gov. Chris Christie may have made a bad impression on the Romney campaign, the New York Times reported: "Mr. Christie is often late, as he was during a $5 million fund-raising dinner in New York City last month," the Times reported, relying on unnamed Republican sources. "After a few uncomfortable moments, Mr. Romney finally had to take the stage and speak first. When Mr. Christie did arrive, it was left to Mr. Romney to introduce him to the crowd."

According to the New Jersey Star-Ledger, "people who keep close watch over the governor's career" think Christie could serve as a good keynote speaker, if not a running mate, at the Republican convention in Tampa.

One final potential vice presidential pick, Louisiana Gov. Bobby Jindal, gave an awkward non-denial on MSNBC last month when asked if he'd be on the ticket: "I'm not going to speculate on hypotheticals," he said.