The 2012 congressional-redistricting cycle following the 2010 census is just about over and done with. And it seems likely to make much less difference than many of us expected. Redistricting is when state legislatures, governors, and commissions draw new lines for congressional districts, after the 435 seats in the U.S. House are reapportioned according to a statutory formula into which are plugged the figures from the 2010 census. I predicted that this cycle, like the 2002 cycle, would produce significant gains for Republicans. Their success in electing governors and legislators in 2010 gave them control in big states like Texas, Florida, Pennsylvania, Ohio, Michigan, Georgia, and North Carolina. And voters in Democratic California approved a ballot measure turning redistricting over to a nonpartisan commission. But the Republican gain turns out to be modest to nonexistent. Charlie Cook’s Cook Political Report estimates the net Republican gain from redistricting at exactly one state. My own estimates track with Cook’s in just about every state and come up with a one-seat Republican gain.
One reason is that Democrats in control of redistricting in Illinois adopted a very aggressive plan that’s likely to cost Republicans four seats. Democrats stretched Chicago districts out through the Cook County and Collar County suburbs to the downstate prairie, and squeezed out Republicans there. The most aggressive Republican plan was in North Carolina, where it replaced an aggressive Democratic plan adopted ten years ago and seems sure to oust three or four Democrats.
In the other big states mentioned above, Republicans concentrated on bolstering current incumbents rather than creating new districts. Big Hispanic-population increases in Texas and Florida forced Republicans to create new Democratic districts.