With his nomination as the Republican candidate for president all but wrapped up, Mitt Romney now faces the challenging task of selecting a running mate. What was once a fairly ho-hum matter (the running gag in the 1931 Gershwin musical lampooning Washington politics, "Of Thee I Sing," is that nobody pays attention to the vice president anyway) is now regarded as a defining moment of a presidential campaign.
Beth Myers, the longtime aide Mr. Romney has assigned to head his vice presidential search, is likely receiving a lot of free advice from a variety of sources. Tea party loyalists and conservatives have made it clear that they expect one of their own to make the cut. Others in the GOP are pressing for a strategic choice that might shore up a specific demographic segment of the voting public.
Looking back over the past several election cycles, however, it's clear that the choice needs to be guided by one overriding principle: Mr. Romney should pick someone the American people are confident is qualified to serve as president and capable of doing so should the need arise.
If there's a thread that ties together the most disastrous vice presidential picks of the past half-century, it's the folly of straying too far from that advice. Sen. John McCain's choice to go rogue with Sarah Palin may have stirred the hearts of party faithful who were thrilled with the Alaska governor's "rock star" qualities, but it quickly became clear in 2008 that she was out of her depth.
While she may have energized the faithful, she appeared so inept during her unscripted encounters with the press — particularly in her infamous encounter with Katie Couric of CBS News — she clearly turned off the independent voters the ticket needed to defeat Barack Obama.
Republicans aren't the only ones to make dubious choices. Sen. George McGovern's selection of Sen. Thomas Eagleton, who not longer after his selection resigned from the ticket when it was revealed that he'd received shock therapy for depression, no doubt contributed to Mr. McGovern's landslide defeat in 1972 (although it was hardly the only mistake the candidate made).
Obviously, vetting a vice presidential candidate's background is crucial. But often, nominees are lured by the siren's song of strategy. That has sometimes involved a desire to win the candidate's home state (Lyndon Johnson and Texas) or simply to balance out the ticket geographically and/or politically (the moderate Sen. Lloyd Bentsen Jr. of Texas chosen by the more liberal Gov. Michael Dukakis of Massachusetts).
But even that approach is far from a sure thing. Whatever voters saw in Walter Mondale's choice of Rep. Geraldine Ferraro, it didn't spur them to support a ticket that went down in flames in 1984. Controversies surrounding Ms. Ferraro's financial affairs may have overshadowed whatever benefit came from choosing a woman as a running mate.
Over and over again, the winning tickets involve safe (and often boring) selections that never cause the bottom of the ticket to upstage the top. Ronald Reagan and George H.W. Bush left no doubt about who had the star power, although the latter was arguably more experienced in government. Bill Clinton picked Al Gore, a fellow white Southerner. And George W. Bush probably wasn't that concerned about winning Wyoming when he chose Dick Cheney as his running mate.
What all three two-term presidents understood was that geography, diversity and balance aren't nearly as important as basic competence (although Mr. Cheney had the added advantage of heading the vice presidential selection process for Mr. Bush). Bad choices are the ones who now seem impossible to have ever imagined occupying the Oval Office. President Spiro Agnew? President John Edwards? President Jack Kemp?
Still, as Mr. Romney is hardly known for his maverick tendencies, such advice may not be necessary. Safe and boring seems to be a mantra not lost on the former governor of Massachusetts. It's difficult to imagine him choosing a loose cannon (sorry, New Jersey Gov. Chris Christie) or even a vanquished foe (Sen. Rick Santorum can probably put away the sweater vests).
That doesn't mean Mr. Romney may not ultimately surprise his supporters, but one suspects that representing a swing state like Florida's Marco Rubio or appealing to a minority group that usually prefers Democrats (there's Mr. Rubio again) won't be enough. It's not the beating hearts of conservatives but the concern of voters about who can be trusted to be a heartbeat from the presidency that should guide the GOP choice.