But acknowledging all of that is not to say that gerrymandered districts don't have a significant impact on the sorry state of American politics. Gerrymandering has leached much of the broader heterogeneity out of congressional districts, contributing to the echo-chamber effect, where members' ideological predilections are reinforced, and not challenged, back home. A corollary is the racial segregation of districts—the fact that so many Republican districts now have barely more than trace elements of minorities, giving GOP lawmakers little incentive to reach out or be sensitive to issues that resonate with those groups. Partisan gerrymandering skews results away from the broader sentiments of voters in a state, as much research, including a new study by Duke University's Jonathan Mattingly and Christy Vaughn, demonstrates powerfully.

And, of course, gerrymandering has helped create a huge number of districts that are fundamentally safe for one party. This is sometimes done by a dominant party in a state "packing" the other party's districts to limit its chances in other districts. Other times it is done by an unholy alliance of both parties to keep all incumbents safe. Gerrymandering adds both to the homogeneity of districts and to making low-turnout primaries dominated by ideological activists the only meaningful elections.

More broadly, gerrymandering moves House and state-legislative elections away from any meaningful responsiveness to the will of the people. And the pattern of lawmakers choosing their voters instead of voters choosing their lawmakers creates more disaffection and cynicism among the public.

Almost every other democracy of significance avoids such problems by creating nonpartisan bodies to draw district boundaries.

How do we reform the redistricting process in this country? Through independent commissions that can use multiple criteria—not just equal population in districts, but factors such as competitiveness, compactness, and communities of interest—to create districts that more closely reflect broader public views. But creating independent commissions is no easy task; doing so through legislative action requires buy-in from the same lawmakers who draw the district lines—and who have the least incentive to give up their power via reform.

With the exception of Iowa, where the state legislature turned the drawing of lines over to a nonpartisan agency in 1981 after disputes and deadlocks handed the power to the Iowa Supreme Court, the one outlet for change has been using the initiative process to implement such commissions. That process worked in Arizona in 2000 and in California in 2008, and while the results are no panacea, the reforms have brought more competitiveness and more fairness to the process.

Guess what? The ability of voters to take control of the redistricting process away from partisan legislators and create a nonpartisan and independent process may disappear next year. The Supreme Court has taken up a case, Arizona State Legislature v. Arizona Independent Redistricting Commission, challenging the constitutionality of the commission. If the Court strikes down the Arizona commission, it will also mean the end of the California commission, and of any future efforts to bypass self-interested legislatures to reform the redistricting process.