Reid Wilson writes at National Journal:
The most dramatic change that redistricting will force upon the country won’t be obvious. Republicans in many states have drawn maps that they believe will shrink the battlefield. Many once-competitive seats have added Republican voters, making them safer for the GOP, and some seats held by Democrats who narrowly won in 2010 have added Democratic voters.
Republicans believe that a total of 14 GOP-held seats and 15 Democratic seats have been shifted into play by the redistricting process. The NRCC believes that six Democrats hold districts that are no longer competitive for Republicans—Reps. Sanford Bishop of Georgia, Gerald Connolly of Virginia, Jim Cooper of Tennessee, Tim Holden of Pennsylvania, Ron Kind of Wisconsin, and Rick Larsen of Washington are the lucky ones.
But the big Republican-friendly shift, they say, comes from once-competitive seats that added big chunks of Republican voters. The NRCC counts 18 GOP-held districts on the list of seats moved off the table. Many Republicans in suburban seats—Reps. Steve Chabot of Ohio, Hultgren of Illinois, Leonard Lance of New Jersey, Thaddeus McCotter of Michigan, Peter Roskam of Illinois, Pat Tiberi of Ohio, and Frank Wolf of Virginia—are on that list. Republicans point to an additional 16 seats they hold that will improve in their favor under new maps, although most remain competitive.
“There wasn’t going to be a lot of net movement of seats that are just won or lost, but that we were going to improve the internals of the overall maps,” said Guy Harrison, who heads the NRCC. “The battlefield has shrunk. And even within that battlefield, it has gotten a little bit better for us.”
Democrats admit that their job has gotten more difficult. The party has fewer targets for its so-called Drive to 25—the number of seats Democrats must win to take back the House—and retirements in conservative districts in North Carolina, Arkansas, and Oklahoma mean the real number of seats they must win is probably in the low 30s. But even those Republican seats that have moved away from Democrats, such as the ones held by Reps. Mike Fitzpatrick of Pennsylvania, Jaime Herrera Beutler of Washington, and Jim Renacci of Ohio, are not completely out of reach.