Like Douthat, I'm a big believer in storyline vice-presidents. Regional balance seems, at times, worse than useless -- it draws attention to your perceived vulnerabilities without actually correcting them. By contrast, picking an amplifying choice -- a war hero with a war hero, for instance -- accentuates your strengths without admitting your weaknesses. So this, from Ross, seems like wise advice for the Obama campaign:
If Barack Obama wins the Democratic nomination, he has an interest in picking a Southern running mate (like Mark Warner, say) less because the pick might help Obama carry some Southern states than because the narrative that such a pick projects - a black candidate with a white running mate from the old Confederacy! - dovetails perfectly with Obama's "beyond our differences" appeal.
Seems unambiguously true. Add in that Warner is relatively young, and his experience is in technology, and you've got a fairly solid choice. The downside is that neither has any foreign policy experience to speak of, but in the end, voters will either trust Obama or they won't.