I feel the far more interesting question is what is specifically wrong with American politics that we cannot get our best and brightest people to wind up as candidates.
I am so over the the overly-partisan rhetoric and seriously don't care which party I'm voting for... I'd just like at least one good choice, preferably two.
It seems ridiculous to me that we cannot do that in this country.
Democrats haven't had a problem recruiting great candidates. Obama is exceptional. Hillary, Biden, Edwards, Kerry... all bright and qualified.
Republicans have had several great candidates: Mitt, Huntsman (meh), Giuliani, McCain, Newt. The problem is the R party hitched it's horse to the southern evangelicals years ago and now cannot get out the way of that stampede. Also the A.M. radio phenomenon has indoctrinated a large swath of the R party. The only way to change things IMO is for either moderate democrats to join and continue demonizing the Tea Party types (not going to happen) or for a highly charismatic moderate candidate to somehow take over the nomination.
Until something changes significantly we will see jackass after jackass coming out of the R party. Paul Ryan is buying his time.