Does Gerrymandering Protect House Incumbents?

by John Sides on October 5, 2009 · 4 comments

in Legislative Politics

I thought I might add that not only do I not believe that gerrymandering is responsible for political polarization, I don’t even think gerrymandering has played a large role in making House seats uncompetitive

That’s Matt Yglesias. He’s correct. Here’s the abstract of a relevant new paper by John Friedman and Richard Holden:

The probability that an incumbent in the U.S. House of Representatives is reelected has risen dramatically over the last half-century; it now stands at nearly 95%. A number of authors and commentators claim that this rise is due to an increase in bipartisan gerrymandering in favor of incumbents. Using a regression discontinuity approach, we find evidence of the opposite effect. All else equal, changes in redistricting have reduced the probability of incumbent reelection over time. The timing of this effect is consistent with the hypothesis that legal constraints on gerrymandering, such as the Voting Rights Act, have become tighter over time. Incumbent gerrymandering may well be a contributor to incumbent reelection rates, but it is less so than in the past.

Emphasis mine. Here are gated and ungated versions of the paper.


TheOneEyedMan October 5, 2009 at 12:49 pm

Wasn’t there an earlier literature on retirement decisions of congressmen that suggested that incumbents strongly feared the redistricting process?

Miles October 7, 2009 at 11:11 am

You can redistrict to ensure a loss in the subsequent election. Is that taken into account? For example, the Ohio GOP will probably feed Jean Schmidt to the wolves by including more of Cincinnati in HD 2 in order to keep HD 1 more competitive.

dende blogger October 7, 2009 at 11:44 am

These findings need to deal with the fact that gerrymandering is done with the explicit intention of making districts less competitive. Why are parties making such an effort to do things that don’t work?

We might sharpen the claim, though. Parties gerrymander so that they can make *some* districts less competitive. In other cases they want to make districts *more* competitive. Take Utah. They have three congressional districts, two of which are very heavily GOP, the other slightly Dem. The Republicans in the state don’t need to make their safe districts safer. They want to make the Dem district more competitive, by stuffing some Republicans from the other districts into it. All three districts become more competitive (for the purpose of making one district more Republican).

There’s also the situation where a state legislature changes the whole map from a Dem-favored one to the GOP-favored one (or vice-versa). That’s going to cause massive turnover during one or two elections, which would balance out much of the seat safety that results from the new gerrymander.

Sebastian H October 8, 2009 at 11:44 am

Dende makes some very good points, and not just in the intentionality issue.

Take the Texas gerrymanders for instance. They very clearly had strong effects–the Democratic gerrymander allowed the Party to retain a large majority with little more than 40% of the total vote. This was a large flip-flop from the previous Republican gerrymander which had similar effects. So the AVERAGE effect on incumbency over the course of the whole period isn’t very large. But the effect on making the seats safe while the gerrymander is in effect is.

So what gerrymandering does is solidify the line drawer’s power again and again until the disparity between voters and representatives becomes too great and then there is an enormous and sudden shift.

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