For a dispassionate analysis, take a look at University of Wisconsin political scientist Charles Franklin’s blogpost in pollster.com. Franklin acknowledges that there has been wide variation in the polls, and concludes: “But no matter how you slice the data, the only reasonable conclusion is that Scott Brown has moved from well behind to a lead somewhere between 4 and 11 points.”

Contrast this with the puzzlement expressed by the ordinarily lucid and thoughtful Michael Tomasky in his Guardian blog.