David Friedman has an excellent post titled "What Should Count as Nutty?" It follows two of his earlier posts on Christine O'Donnell. A couple of excerpts:
In trying to make sense of all this, I fall back on the observation that most of what most of us, perhaps all of us, believe, is based not on evidence directly available to us but on what the people around us tell us. Not only is it so based, it has to be. Nobody has the time and energy to check enough of the facts for himself--to be sure that Australia, and New Zealand, and Antarctica, and Orford, N.H., actually exist by going and looking at them, rather than by believing what he is told or reads.
The whole thing is worth reading. One of the things I like most about the it, besides the argument itself, which is very good, is the compassion that David shows.
The piece offers two other pieces of evidence against O'Donnell. One is that someone who worked for her 2008 senatorial campaign reported that O'Donnell "told me that she thought Joe Biden tapped her phone line." If Moynihan believes the idea that political campaigns sometimes engage in illegal wiretapping is absurd, he somehow managed to miss the entire Watergate episode along with much else.