Forecasting Control of State Governments and Redistricting Authority After the 2010 Elections

Abstract

This article makes forecasts for the 2010 state legislative and gubernatorial elections. These forecasts indicate the Republicans will add control of 15 legislative chambers and nine governor’s offices, leaving them with 51 chambers and 32 governorships. Forecasts about the extent of redistricting authority by the Democratic and Republican parties indicate the Republicans will have authority over 125 U.S. House seats, while the Democrats will have authority over 62. In a chamber level analysis of 2,141 legislative and a state level analysis of 758 gubernatorial elections, four national forces are used in predicting election outcomes from 1950 to present: presidential approval, change in per capita income, midterm loss, and the percentage of respondents who say they will vote for a Democrat for the U.S. House. The differential effect of these forces in states with the straight-ticket option is also taken into account. Monte Carlo simulation that takes into account states’ different rules regarding redistricting authority is then utilized to assess how many U.S. House seats the Democratic and Republican parties will control.