Stu Rothenberg always has excellent instincts, and I think he really nailed it this week with his column on congressional redistricting:
Redistricting probably won’t be a windfall for the GOP in terms of adding new seats because the party was so successful in November. After their huge gains, Republican mapmakers in many states won’t be able to shore up Republican freshmen in districts that they never should have won and, at the same time, also eliminate more Democratic districts.
But the likelihood that Republicans will “only” be able to cement their strong position in the House rather than add to it is hardly grounds for celebrating by Democratic strategists. And that outcome certainly wouldn’t preclude the view that, ultimately, redistricting could be disastrous for Democrats.
As President Obama might say, Republican state legislatures will be "saving jobs" for themselves in the biggest states (Ohio, Pennsylvania, Michigan, Florida), and they'll have room to create new opportunities for themselves in only a few large ones (North Carolina, Georgia, Texas).
But the current Republican House majority is the party's largest in 60 years. If, after taking new Democratic opportunities into account (in Illinois, for example), redistricting puts a bar of "normal" above or anywhere near the 242-193 of the current Congress, then Democrats will have lost decisively.