There's a hit piece up on Reuters today attacking logical GOP vice presidential choice Marco Rubio, hitting him on everything from his personal finances to his (supposed) lack of appeal to non-Cuban Hispanics. Among other things, it has him voting against Sonia Sotomayor, which is flat-out wrong (she was confirmed in 2009 and he didn't arrive in the Senate until 2011), so I have no idea how accurate the rest of the stuff that's being thrown at him might be.
Will Rubio be the VP choice? I don't think anyone can predict it; these choices are highly idiosyncratic. As far as I know, all we can say is that sometimes the nomination runner-up gets the pick (Lyndon Johnson, George H.W. Bush, John Edwards), and sometimes it's someone else. But Rubio would seem to be logical in some senses, what with being from a large swing state and presumably appealing to a large, important demographic group, whatever Reuters wants to tell us.
Logical, except as the article reminds us, for one thing: he hasn't been vetted by a presidential nomination campaign. As I've said, that's really the thing that's separated the awful selections (Richard Nixon, Spiro Agnew, Tom Eagleton, Gerry Ferraro, Dan Quayle, Sarah Palin) from everyone else. In which "awful selection" means that they either were significant campaign problems or, if elected, resigned to avoid jail time. There's simply no better vetting process than a presidential campaign. Of those who went through one, only John Edwards really turned out to be a serious problem, and that was years later; he was fine during 2004. VP candidates Jack Kemp, George H.W. Bush, Joe Biden, and Al Gore all were just fine (as were Lloyd Bentsen and Walter Mondale, each of whom had previously sort-of run, although I wouldn't count those races for this exercise.
The problem, for the Republicans, assuming Mitt Romney is the nominee, is that they're not doing a great job of producing a pool of presidential candidates who have been vetted by a campaign while also holding orthodox views on policy positions the party cares about and having conventional credentials. This round, we have Rick Perry, who was vetted but found wanting; he seems an unlikely pick. Tim Pawlenty diminished himself with his run, and at any rate really didn't stay in long enough to have received the press attention that vetting requires, although it's probably better than nothing. Maybe Rick Santorum? He doesn't really have conventional credentials, since those usually don't include an electoral drubbing, but maybe.
OK, last time around. Fred Thompson is old and hasn't been in office for almost a decade; nope. Rudy Giuliani? Obviously not. Not the fringe candidates, or the ones who dropped out very early (Sam Brownback ran? Oh yeah). There is one, though: Mike Huckabee.
If you go back to 2000, you could add Lamar Alexander, except that he's even older than Fred Thompson, and you could also perhaps add John Kasich.
If Romney asked me for advice, I'd probably say that the do-no-harm list is Pawlenty and Huckabee, and I'd be very much leaning towards the Huck. But the other part of this is that if for whatever reason Romney or important GOP groups find both of them unacceptable, then Romney will wind up with someone who hasn't been through the process. And while that certainly can work, it's a risky move with very little upside.