That’s the question Eric McGhee and I address at Wonkblog today, building on some previous posts of his and mine on this blog. Here’s a sample quote:
The analysis above does not confirm the worst fears about the “great gerrymander” of 2012. But given the challenge of answering “compared to what?”, we would not argue that the 2011 redistricting gave the GOP no advantage whatsoever. Political science research on redistricting has confirmed that control of the line-drawing process does yield some benefits. The challenge is in estimating what those benefits are. We have tried to show that the answer is far more complicated, and that the magnitude of the redistricting effect is probably smaller than many have assumed.
The whole post is here.