Neetzan Zimmerman translates:

Christine O’Donnell: She’s not a witch. She’s you. Unless you’re a witch. In which case, she’s not you. Because she’s not a witch.

Will Bunch analyzes:

[T]he rise of anti-elitism as the most potent force in 2010 is also highly understandable. The social changes in America since World War II -- in which a college education is the only path for rising above our stagnant middle class and yet that opportunity is unaffordable for millions -- is part of a cauldron of inevitable social-class resentments that have been brewing for 50 years or more. The reason that cauldron (notice the witchcraft allusion!) is now boiling over is that the college-know-it-alls seem to have been running things for a while now, and yet we get a financial crisis nearly wiped out America and left us with 10 percent unemployment.

"You" could have done that, right?

Weigel's addendum:

It's been obvious that O'Donnell's campaign relishes the old tape of her discussing her high school witchcraft date, because it allows her to pretend that every story about her is just as silly. Of course, the reasons why she was battered by the News Journal, some conservative elites, and Democratic TV ads have nothing to do with the witch moment.