Ezra Klein yesterday offered a helpful list of "The 13 Reasons Washington is Failing." I recommend it, but I do want to quibble with his characterization of redistricting. As Ezra says,
Whether it affects the partisan balance or not, it clearly packs candidates into less representative districts — which makes it easier for them to ignore popular will.
In fact, that's not at all clear. Sometimes redistricting does precisely the opposite.
There are typically two major strategies a state legislature will pursue when conducting a redistricting:
- Protecting incumbents. When this is done, districts are drawn to make incumbents safer -- Republican districts become more conservative, Democratic districts more liberal. This could contribute to polarizing the legislators who represent those districts; they are less likely to be punished for extreme behavior. This strategy is often pursued when a state has split party control, and protecting all incumbents makes everyone happy.
- Enhancing the majority party's share of seats in the chamber. When this is done, many districts are redrawn such that they become more competitive. This gives the majority party a better chance at expanding its numbers. You don't need all your members winning with 80% of the vote if they can still win with 65% of the vote and give you a shot at winning a few more seats. Notably, this form of redistricting contributes to depolarization -- legislators become more likely to be punished for extreme behavior. This strategy is often pursued when a state government is under unified party control.
As should be clear, these strategies work against each other. To the extent that you're protecting incumbents, you're not increasing your party's seat share, and vice versa.
And yet we frequently hear claims that the 2012 redistricting did both at the same time. In the post linked above, Ezra is claiming that the redistricting made Republican seats safer. And here's an NY Times piece claiming that it gave Republicans greater seat shares.
Now, of course, some states may be pursuing the first strategy while other states are pursuing the second. And, in fact, the political science evidence on this front (see here, for example) suggests that the effect of redistricting on polarization is marginal, if it even exists. But if it does exist, let's try to be clear about what redistricting is doing, and not simply blame it for whatever we currently don't like about politics.