Then again, maybe Rubio’s inability to win a GOP primary exposes a fatal flaw. It’s possible that enduring a primary campaign tests someone’s character, toughness, and mettle. Campaigns face scandals and crises and hardships, and the ability to overcome these things does tell us something about you. Maybe the voters know more than I do? Maybe there’s something bad about Rubio that the wisdom of the crowds can sniff out?

This theory argues that, by definition, the best candidate always wins the primary.

This strikes me as dubious. Some of the attributes required for winning a primary seem utterly arbitrary. Let’s suppose you happen to be terrifically popular in Iowa and New Hampshire. You would have a decided advantage, even though this accounts for just a small fraction of the votes that would matter in a General Election.

Other important factors may have little or no correlation to actually governing. The ability to organize a caucus, for example, might speak to your ability to win a general election, but does it demonstrate the kind of leadership and strategic thinking and organizational ability that would come in handy in the Situation Room? You’d be hard-pressed to argue that it does.