I mentioned yesterday in my post on Evil that I could imagine voting for Palin. Fivethirtyeight.com's Nate Silver has ten reasons why she might win the Republican nomination (HT to Chip Gagnon). He forgets to include one of the key factors that produced Jesse "The Body" Ventura as Governor of Minnesota a few years ago--the drunk frat boy vote [DFBV]. That is, there might just be enough people out there to swing a multi-candidate election just because it would amuse them (also see California's recall election). This would not help Palin win against Obama as the DFBV is likely to face the sobering effects of the electoral college.
As I have posted before, having two responsible parties is better than having one (or a semi-one). If the Republicans completely lose their grip on reality and become a marginal party, then American democracy will suffer--whether they achieve California-levels of blocking reasonable action or not.