Nate Silver: Projected Republican Gains Approach 50 House Seats [View All]

[tritsofme]

It has become fashionable to speak of a Democratic comeback, but we’re not really seeing one in our forecasting models. Certainly there are some individual races — particularly on the East and West Coasts, as well as some gubernatorial contests outside these regions — that look better for Democrats than they did a few weeks ago. But we’re showing Republicans gaining ground where they need to gain it to maintain decent chances of taking over the Senate. We also show improvement for them in the House forecast this week.

Our model now estimates that the Republicans have a 72 percent chance of taking over the House, up from 67 percent last week. Moreover, they have nearly even odds of a achieving a net gain of 50 seats; their average gain in a typical simulation run was between 47 and 48 seats. However, the playing field remains very broad and considerably larger are possible, as are considerably smaller ones.

Republican gains this week are mostly the result of factors at the local level; the national environment is roughly stable. The expert forecasters whose judgment we incorporate into the model continue to revise their characterizations of races, and in almost all cases, the changes work toward the benefit of Republicans. Cook Political, for instance, in a break from its usual convention of not classifying seats held by incumbents as worse than toss-ups, this week decided to classify 10 seats currently held by Democratic incumbents, including the seat held by Alan Grayson in Florida’s 8th Congressional District, as leaning toward the Republicans.

Polls of individual House districts, while more varied, also generally contained good news for Republicans this week. A series of polls conducted by Penn Schoen Berland for The Hill, for instance, found 11 of 12 first-term Democrats that tested trailing their Republican opponents. The polls ought not have been terribly shocking to Democrats — our model already had the Democrats favored to lose all but one of these seats — but they nevertheless confirm that the principle of “last hired, first fired” often holds in “wave” elections, and than many of the Democrats who won their seats for the first time in 2006 or 2008 will likely lose them this year.

http://fivethirtyeight.blogs.nytimes.com/2010/10/08/projected-republican-gains-approach-50-house-seats/

If nothing else, it will interesting to analyze the accuracy of these predictive models after election day.