I'm very interested to learn more about the issue of redistricting. I just shared with a friend my optimism for the coming Supreme Court case regarding the constitutionality of partisan gerrymandering. Previous opinions and on-the-record statements by Justices suggest that partisan gerrymandering is probably unconstitutional, though has stayed on the books because there is no reliable legal standard to determine what clearly constitutes it. A few promising standards have been developed in the last few years (having to do with statistical analyses... I can provide a link to an explanation, but suffice it to say that the standard for partisan gerrymandering has to be a bit more rigorous than "you'll know it when you see it.")
This friend I'm talking to just wrapped up a yearlong stint at the National Governors Association, having met a large number of governors and their aides. He's not a professional political scientist, nor a statistician. But he says that, according to some insiders he rubs shoulders with, gerrymandering is partially working to Democrats favor insofar as the Republican advantage is geographic, so drawing maps that are "contiguous" and not gerrymandered would favor the Republicans. See What This 2012 Map Tells Us About America, and the Election.