There have been a couple of good pieces I've read over the last couple of weeks that encapsulate the dilemma that faces those in control of the redistricting process.
Carl Bialik dips into the political science literature and finds while redistricting has an impact, it is limited by a host of factors.
Aaron Blake hits on some of the same themes, but does so through a case study of the dilemma facing Republicans in Texas.
Given the GOP's run through gubernatorial and state legislative races two weeks ago, the party has a distinct advantage in a series of states where they control the redistricting process. That said, those state governmental advantages may have a limited impact due to the question posed at the outset. The temptation of the former is tough to resist for any party that has unified control of a state government, but the latter is a pragmatic option that offers a safer and longer term effect. None of this is to suggest that the Republicans won't gain seats as a result of their victories on the state level. Rather, the point is merely to highlight the fact that parties with unified control of their state governments can only carve out so many additional districts for themselves before they begin to hurt the incumbents of their own party. That goes for Republicans and Democrats.