Breakdown of GOP victories

For all you junkies out there, Nate Silver has an interesting breakdown of the GOP wins in NY-9 and NV-2 last night. He uses a broad measuring stick known as the Partisan Victory Index (PVI) to calculate how big a victory was scored. The PVI is "a measure of how the district voted relative to others in the past two presidential elections." He is warning Democrats that it is beginning to look a lot like 2010: The Nevada Second, for instance, has a P.V.I. of Republican plus-5, meaning that the Republican candidate would be expected to perform 5 points better there than a Republican might nationally. Since a vote for the Republican is (usually) a vote against the Democrat, you need to double that number to project the margin of victory. In this case, that would imply a Republican win by 10 points given average candidates and a neutral overall political environment. The Republican Mark Amodei, however, leads by 22 points as of this writing, an easy victory, meaning that he overperformed...(Read Full Post)