Underscoring a point I've made several times in the last week, Alan Abramowitz, a respected political scientist at Emory University, has a new analysis showing that the Virginia and New Jersey gubernatorial results are not predictive of midterm election seat changes:
[T]he results of the previous year's gubernatorial elections in Virginia and New Jersey did not predict the results of the midterm elections. Not only is the estimated coefficient for the Virginia/New Jersey election variable small and statistically insignificant, but it is in the wrong direction: the better Republicans did in Virginia and New Jersey, the worse they did in the subsequent midterm election.
A forthcoming paper in Legislative Studies Quarterly (via John Sides at The Monkey Cage) finds that changes in partisan control of House seats in special elections is predictive of general election outcomes. In the current context, these results suggest an environment that is slightly more favorable to Democrats due to the pickup in NY-23 (the only partisan change in a House special election this electoral cycle).
In reality, of course, Democrats will have a tough time in 2010 -- I fully expect them to lose a significant number of seats. But contrary to the media hype, the Virginia and New Jersey results don't provide much information about what that outcome is likely to be.