The Size of the Current Swing Vote

Those of you who read TDS' Swing Voter roundtable earlier this year will remember that there's a lot of disagreement about how to define swing voters. But such disagreements tend to shrink in the course of actual campaigns, as, gradually, the universe of potentially persuadable and motivatable voters converges with "undecideds." In his Wall Street Journal column today, Karl Rove, casting about for reasons to be optimisitic about John McCain's campaign, suggests that there are "probably more undecided and persuadable voters open to switching their choice than in any election since 1968." At FiveThirtyEight.com, Nate Silver decided to test Rove's assertion with actual data. Using the "unaccounted for voter" percentage in the last Gallup Poll (chosen because it's been around forever), Silver compares that to the number at... [read full story]