When New Hampshire Sen. Kelly Ayotte joined Mitt Romney for a tour of fishing boats last week, she was auditioning.
When Florida Sen. Marco Rubio turned up with Romney two weeks ago in Delaware County, maybe he was, too.
In the weeks since Romney clinched the Republican nomination, many of his campaign events feel like running-mate tryouts, with potential vice presidential picks joining him, one after another, to be scrutinized for compatibility and appeal.
Partly, this is a clever way for Team Romney to maintain interest during the news-light lull between the end of GOP primary hostilities and the late-summer nominating conventions. But clearly vetting has begun, with a team in the campaign's Boston headquarters assembling to comb through the lives of possible ticket-mates as strategists weigh how each might help - with geography, key demographics, and conservative elements of the party who have remained wary of Romney.
Handicapping the veepstakes is a favorite quadrennial spring pastime. Who can swing an important state for your presidential nominee? Who's got game with an up-for-grabs ethnic group? Who provides ideological or temperamental balance? These questions will be asked and answered countless times until Romney announces his decision, and maybe even after.
So far, several leading contenders have campaigned with Romney: Rubio (swing state, Hispanic, popular with tea party); Virginia Gov. Bob McDonnell (social conservative, swing state); Wisconsin Rep. Paul Ryan (young, conservative, swing state, fiscal expertise); former Minnesota Gov. Tim Pawlenty (evangelical, blue-collar appeal); and Ohio Sen. Rob Portman (fiscal expertise, swing state), among others.
Rick Santorum, who finished second in the primaries and met with Romney on Friday in Pittsburgh for a 90-minute chat, was Republican voters' most popular choice for veep in a Reuters poll last week, clocking in at 18 percent. He has strong credentials with social conservatives, but could be anathema to independents.
And then there's New Jersey's Gov. Christie, who drew huge crowds when he stumped for Romney in Iowa and New Hampshire with his in-your-face charisma. He had been pouring cold water on all the vice presidential talk, but last week said Romney "might be able to convince me. He's a convincing guy."
Yet would the big guy overshadow the head of the ticket? No doubt that's being considered.
Casting a shadow over the process is the 2008 debacle of Sarah Palin, plucked from obscurity by Sen. John McCain when he needed a jolt of energy. The first-term Alaska governor had not been well-vetted, however, and the large gaps in her knowledge made her a liability to the campaign.
Many Republicans say Romney should settle on a solid choice whose competence to serve is clear; that consideration is bringing names like Pawlenty and Portman, the former director of the Office of Management and Budget, to the fore.
"The winning choice is the dull choice," former New Hampshire Gov. John Sununu, a Romney adviser, argued in a recent op-ed in the Dallas Morning News.
"I'd like to think I'm a serious legislator and trying to get things done," Portman told Fox News last week. "That's my goal in life, is to get things done. It's not about sizzle for me. . . . I mean, America made a decision in 2008 to go with a president who did have sizzle. And look, he was kind of a celebrity. He also had a very compelling message which was, remember this, 'I'm going to bring people together to solve problems.' Didn't happen. And it didn't happen because he didn't have the experience, he didn't have the record."
Ultimately it will be Romney's decision alone, of course. And his career in business and as governor of Massachusetts shows him to be a cautious, data-driven manager who values competence.
"He has a history of surrounding himself with the best and the brightest people," said GOP strategist Bruce Haynes, of the Washington-area firm Purple Strategies. "Romney is not just going to look for a good complement on the ticket; he's going to look for a good partner who will help him make the best decisions for the country. That's just how he's wired."
For all the talk of strategic ticket-balancing, experts gauge that running mates have had a negligible effect on general-election outcomes, at least since 1960, when JFK's selection of Lyndon B. Johnson helped the Democrats carry Texas.
Detailed studies of historical exit-poll data show that voters' partisan leanings, ideologies, and assessments of the presidential nominee are the dominant factors driving their choices.
"Statistically speaking, vice presidential choices really don't contribute anything at all on average to the likelihood of an individual voting for or against a presidential candidate," said David W. Romero, a political scientist at the University of Texas at San Antonio who authored an influential 2001 study on the topic.
The title of that study? "Requiem for a Lightweight."