Penn, we hardly knew ye . . .

I don't have a terrible lot to say about the Mark Penn affair. Obviously, his departure is a terrible loss for the campaign. I wouldn't call this "the worst possible moment"--but heading into a make-or-break primary is certainly one of the last times you want to see this kind of change. They, and all of their supporters, have to be wishing that they had gotten farther out in front of the news cycle on this one, doing their best to head it off before it turned into a major political setback.

But whatever mistakes the campaign made, I hardly see this as a fatal blow. They surely could have handled it better, but its not clear to me that Obama really could have stopped Mark Penn from leaving, and thereby creating a vacuum into which someone competent might step. This probably increases the probability that Hillary will win somewhat--but a 30% increase in a 1% chance isn't really enough to get excited about.