Redistricting Myths and Realities

by Robert Sanders

Most politicians will tell you that redistricting helps the majority party stay on top, but a new study shows that redistricting tends to make the political process fairer and more competitive, no matter which party controls it.

Redistricting, the redrawing of legislative district boundaries, is most common after new census figures are released every 10 years, and can be among the most contentious and partisan activities in politics.

One party often controls the redrawing of district lines, and explicitly tries to benefit at the expense of the other. Hence, even though required by the US Constitution, redistricting has been universally reviled as allowing one party to tinker unfairly with the rules.

"Contrary to the assumptions of politicians and political scientists, redistricting tends to make legislative elections more competitive," says Andrew Gelman, assistant pro-fessor of statistics. "People often ask whether redistricting harms democracy? The answer is no. The system as it stands works pretty well."

Gelman and Gary King, professor of government at Harvard, published their analysis of redistricting and its effects on elections to state legislatures in September's American Political Science Review.

"Redistricting always has been seen as something nasty," King says. "We've shown for the first time that, while it may be nasty, it is a beneficial component of democracy."

One of the main reasons, the authors say, is that current laws rein in partisan shenanigans. Though they vary from state to state, laws governing redistricting typically stipulate when and where districts can be redrawn, protect minority blocs, and mandate districts be compact and not split natural clusters such as towns.

True, the authors say, a redistricting plan controlled by Republicans helps Republicans more than a Democratic-controlled plan. But redistricting controlled by either party reduces the overall level of bias toward either party, compared to what would happen if there were no redistricting.

"When you design districts you are constrained by laws, and the laws work," King says.

"While it's true that the people in control of redistricting want to control their own party's seats, they don't have absolute power," Gelman adds. "Even in partisan redistricting there are compromises."

Redistricting plans almost invariably land in the laps of judges who are asked to rule on their legality, King says. This forces partisans to draw lines in anticipation of judicial review of their actions.

The two researchers wrote a computer program called JudgeIt that allowed them to predict various measures of the fairness and competitiveness of elections and redistricting plans.

JudgeIt, which Gelman and King distribute free, can also help predict individual election results, and it can answer "what if'' questions, such as what would happen if term limits were imposed.

JudgeIt was used during the recent redistricting process in roughly half the nation's 50 states by or on behalf of the federal courts, Democrats, Republicans, third parties, non-partisan organizations, minority groups, members of congress, state legislators, the US Justice Department, other government officials, and private citizens.

JudgeIt also won the American Political Science Association's Research Software Award for 1992.

Generally what JudgeIt shows is that redistricting has an effect similar to that of legal term limits, King notes.

"That's what redistricting does, it makes lots of incumbents get out. It rejuvenates and reinvigorates the political system. It sends even popular incumbents scurrying back to their districts to meet and build support among their new constituents."

"Even the party in power hates redistricting," Gelman adds. "It shakes up the system for both parties, increasing everyone's chances of losing and encouraging incumbents to retire."


Copyright 1994, The Regents of the University of California.
Produced and maintained by the Office of Public Affairs at UC Berkeley.
Comments? E-mail