Republicans are getting depressed under an avalanche of polling suggesting that an Obama victory is in the offing. They, in fact, suggest no such thing! Here’s why: 1. All of the polling out there uses some variant of the 2008 election turnout as its model for weighting respondents and this overstates the Democratic vote by a huge margin. In English, this means that when you do a poll you ask people if they are likely to vote. But any telephone survey always has too few blacks, Latinos, and young people and too many elderly in its sample. That’s because some...