Biden For President?

My colleague and friend Jonathan Chait, in perhaps the oddest column of the entire saga, said Biden would be a "terrific" president and that his Obama quote was "widely misunderstood," but that he should drop out of the presidential race nonetheless, because he's gaffe-prone and thus can't win. This strikes me as a strange conflation of the descriptive and the normative. If Biden wants to waste his time in a quixotic bid for the presidency--a job Chait thinks he'd do extremely well--why stop him?