Should the political momentum favor the Republicans this year, as seems likely, they have picked an auspicious time for it. This year’s gubernatorial elections are unusually important because of the role that some governors play in redistricting, the process of dividing the nation into 435 Congressional districts that occurs after each Census. Redistricting is often a contentious process, but it is especially so in states that are bound to lose seats in Congress. The result can resemble a game of musical chairs, with too many incumbents vying for fewer districts. Among the states expected to lose seats are Iowa, Michigan, Ohio and Pennsylvania – all states where the Republican nominee has emerged as a clear favorite.
Gubernatorial races, especially open races, are often quite dynamic until the last hours of the campaign.
Thus, most Democrats who are now trailing have a chance to come back. In Michigan, for instance, where Virg Bernero, a Democrat and the mayor of Lansing, is running against the venture capitalist Rick Snyder, the number of undecided voters is high and the race is likely to tighten, although perhaps not enough for Mr. Bernero to secure victory.
Nevertheless, both the math and the clock are working against the Democrats, and even if the Republicans do not do win 30 seats, they have a 95 percent chance of controlling at least an outright majority of governor’s mansions, according to the model.
This is the debut of FiveThirtyEight’s gubernatorial forecasts, which will be updated approximately once a week until the elections. The methodology behind them is similar to FiveThirtyEight’s Senate forecasting model, in that they are informed by a rigorous statistical analysis of election outcomes since 1998. However, the gubernatorial model also contains a number of important differences: economic variables like unemployment, which have greater predictive power in gubernatorial races than in Congressional races, play a more explicit role, for instance.
In addition, gubernatorial races have a greater statistical tendency to regress to the mean -– that is, to tighten as the election draws closer –- even if the polling is initially lopsided. These distinctions will be discussed at more length in subsequent articles.
http://fivethirtyeight.blogs.nytimes.com/2010/09/03/g-o-p-poised-to-control-30-governors-seats/