The ideal running mate for Mitt Romney would make three simultaneous contributions to the Republican ticket:

1. Reassuring the general public that he (or she) is competent, scandal free, and ready to assume the daunting responsibilities of the presidency;

2. Inspiring the conservative base and provoking the sort of ecstatic enthusiasm that the presidential nominee might not generate on his own;

3. Freshening and broadening the Republican brand by refuting Democratic claims that the GOP remains a country-club party of rich, old, white males.

The third goal looms as especially important in 2012, with the Obama reelection team determined to stigmatize Republicans as incurably racist and hopelessly out of touch. According to anonymous but frequently quoted sources in the president’s campaign, his strategists have mostly given up on winning over white males: last time, after all, they lost pale-faced Anglo guys to John McCain by a landslide of 16 points (57 to 41 percent). While white voters (male and female) composed an overwhelming 74 percent of the electorate in 2008’s historic election, and went for McCain-Palin by a solid margin of 55 to 43 percent, Obama-Biden still managed to sweep to White House on the strength of commanding margins from the one quarter of the voting public identified as nonwhite or Latino. In November, the Obama strategy aims to rebuild those lopsided majorities among people of color while simultaneously making major inroads among white voters who also happen to be young, gay, or single females.

No one in the Romney camp discounts the potential of this Democratic plan and their fears of a reassembled “minority coalition” feed frequent speculation over an “unconventional” GOP choice for vice president. According to this logic, by selecting a Latino, black, or female running mate, the Republican nominee could limit the president’s huge advantage among one of his most important target groups while sending powerful messages to the rest of the country that today’s GOP rejected the obnoxious idea of a political party drawing nearly all its support from the nation’s white majority. 

While the theory sounds plausible enough, it runs into trouble when applied to most of the specific names most commonly suggested for second spot on the Republican ticket. Governors Bobby Jindal of Louisiana, Brian Sandoval of Nevada, Susanna Martinez of New Mexico, and Nikki Haley of South Carolina, as well as U.S. Senator Kelly Ayotte of New Hampshire and U.S. Representative Cathy McMorris Rodgers of Washington are all formidable public servants and accomplished communicators, but each of them would also face potential challenges as an “affirmative-action selection”—raising suspicions that they’d been chosen because of membership in one or more key electoral constituency rather than a record of outstanding achievement.  

Because none of these potential nominees has yet established a big national reputation, they would also suffer from the Sarah Palin/Dan Quayle Factor—where the surprising nature of the choice provokes inevitable doubts about qualifications for the job and generates an instant avalanche of unflattering media scrutiny. Palin herself faced the sort of questions (“Name the major newspapers you read every day?”) that no reporter dared to ask the Washington veteran Joe Biden while even the most trivial nonscandals from her past (did she really push to remove racy books from the shelves of the Wasilla library?) got the sort of microscopic attention that a politician with a long career in the public spotlight would never draw. In other words, while any of the rising young conservatives would easily satisfy criterion No. 2 and help to rally the right-wing base, they could run into major trouble on goal No. 1: reassuring the public as to their sure-footed competence and preparation for the job.

Moreover, the actual electoral impact of a ground-breaking choice is often overstated: even with Sarah Palin on the ticket, John McCain earned a smaller majority among white female voters than did the macho-man ticket of George W. Bush and Dick Cheney in the two previous elections. Similarly, some pundits suggested that 41-year-old Dan Quayle, as the first baby boomer ever selected for a national ticket, would draw a big surge of support from the potent boomer voting bloc in 1988. As it turned out, however, George H. W. Bush got far more support from that postwar generation when he ran as the running mate of the genial geezer Ronald Reagan than in either of his two campaigns with the youthful Quayle.

If Romney looks to emphasize proven competence rather than precedent-shattering excitement, he’s left with a group of mostly boring white, male Republicans from central casting and one prominent white male contender who’s far too un-boring for serious consideration. Chris Christie’s brawling, confrontational style might delight conservative true-believers but would produce a series of big, angry fights with press and public that could easily upstage a candidate at the top of the ticket best known for his calm, buttoned-down, unflappable demeanor. A Romney pledge to make good on Obama’s broken promise to put an end to polarization and petty bickering in Washington becomes instantly less credible with Christie on the ticket.  

As to the other prominent names on the commanding and experienced list (Gov. Bob McDonnell of Virginia, former governor Tim Pawlenty of Minnesota, Sen. Rob Portman of Ohio), none of them would damage the Romney campaign but none of them would deliver a new jolt of passion or a spurt of base-broadening either. Portman, according to some reports the current frontrunner to get the nod for the job, brings special problems due to his two years as budget director for George W. Bush. For Democrats, Portman’s selection would provide welcome confirmation of their endlessly-repeated claim that “the Republicans want to take us back to the failed policy of the past.” The last subject the GOP wants to discuss as the campaign unfolds would be the budgetary decisions of the still-toxic Bush 43, but with Portman on the ticket those conversations become unavoidable.

The shortcomings of each of the other prominent contenders should drive Governor Romney back to the one potential candidate who could conceivably satisfy all three goals of the perfect vice presidential nominee: Sen. Marco Rubio of Florida.

No one could generate more exhilaration on the part of the party’s conservative base since Rubio’s election in 2010 represented the most celebrated of all victories for the Tea Party movement.

At the same time, Rubio possesses an utterly unique ability to allay fears that he’s not ready for prime time because he’s been a darling of the national media for more than two years, with at least as much television exposure over that period as any other member of the Senate. He won election to the Florida legislature at age 28 and took over as the most important leader of that body–speaker of the House–seven years later.

Most importantly, he wouldn’t receive the sort of grilling and hazing that Sarah Palin and Dan Quayle endured because his nomination would in no sense count as a surprise: for more than a year he’s been prominently considered a lively vice-presidential possibility. No political journalist in any corner of the country would feel shocked if Romney chose Rubio, nor would they need to start digging for information on an out-of-nowhere choice, asking themselves “Marco who?”

Senator Rubio, in short, has already been vetted, with the brutal, three-way battle for his Florida Senate seat drawing intense scrutiny from national as well as local reporters, resulting in microscopic examination of a series of potential scandals. Yes, the Rubios compiled an imperfect record in their handling of money, with unpaid student loans, a shared second home that barely escaped foreclosure, and inappropriate (and now fully repaid) charges on a Republican Party credit card during his service as state House speaker. None of these foibles gained traction during his Senate campaign, and he explains them in some detail in his endearing new bestseller, An American Son. In fact, he comes across as a more sympathetic everyman as a result of his past struggles: no one could claim that Senator Rubio, whose mother worked as a maid and whose father toiled as a bartender, counted as out-of-touch with the challenges of ordinary citizens.

And as to the senator’s historic status as the first Latino on a national ticket, the press would no doubt make much of that distinction for weeks after his selection, but no one should expect an instantaneous edge with Hispanic voters. The real importance of Rubio’s background as a 41-year-old son of Cuban immigrants amounts to a decisive alteration in the GOP image at the very moment that Democrats seek to characterize the opposition party as an exclusive club of rich old white guys. As much as his Spanish fluency and his inspiring up-from-the-bottom personal narrative, Rubio’s age would give Democrats fits. He’s a full decade younger than Obama, and 29 years younger than Joe Biden; in fact, Biden won election to the U.S. Senate when Marco Rubio was only one year old.

Any Republican who doesn’t relish the prospect of a Rubio-Biden televised debate hasn’t watched the Florida senator in his masterful handling of even the most contentious media interviews.

As a meticulous, methodical, congenitally cautious businessman, Mitt Romney will analyze every aspect of his vice presidential choice and almost certainly avoid the sort of Hail Mary play that John McCain tried with his nomination of Sarah Palin. Romney will appropriately attempt to balance competing needs to impress pundits with a responsible, seasoned selection, to rally the conservative faithful with a thrilling true-believer and, if at all possible, to broaden the party’s base and to shatter hostile stereotypes. For 2012, Senator Marco Rubio presents an unprecedented opportunity to satisfy all three demands, at a rare moment when the most reassuring candidate could also count as the most exciting.