Since the 2000 cycle, these Republican gains have locked in and even expanded. To see how this was done, I asked Nathaniel Persily, a genial assistant professor of law and political science at the University of Pennsylvania, to visit my office and bring his laptop. Persily, who is thirty-three, has built a reputation as a nonpartisan expert and occasional practitioner in the field of redistricting.
Before 1990, most state legislators did their redistricting by taking off their shoes and tiptoeing with Magic Markers around large maps on the floor, marking the boundaries on overlaid acetate sheets. Use of computers in redistricting began in the nineties, and, as Persily demonstrated, it has now become a science. When Persily opened his computer, he showed me a map of Houston, detailed to the last census block. (The population of each block usually ranges from fewer than a dozen to about a thousand.) "This is the same map that DeLay's people used to redistrict," Persily said. Indeed, DeLay's political operation purchased ten copies of the software, which is called Caliper's Maptitude for Redistricting and costs about four thousand dollars per copy. The software permits mapmakers to analyze an enormous amount of data-party registration, voting patterns, ethnic makeup from census data, property-tax records, roads, railways, old district lines. "There's only one limit to the kind of information you can use in redistricting -- its availability," Persily said. (In Pennsylvania, Republicans used Carnegie-Mellon University's mainframe computer, which would have allowed them to add even more data, such as real-estate transactions.)
With a few clicks, Persily changed the map from one that showed party registration in each census block to one that revealed voting results in each block. The colors ranged from dark red, for heavily Democratic votes, to dark blue, for strongly Republican. He showed voting results in about two dozen races, from President to governor and from congressman to local offices. "The whole process has got much more sophisticated," Persily went on. "Party-registration data are not the only kind of data you want to use. You want to use real election results. That's a big change from ten years ago. We have become very good at predicting how people are going to vote. People's partisanship is at a thirty-year high. If I know you voted for Gore, I am better able to predict that you are going to vote for any given Democrat in a future election."
I asked Persily to give me a demonstration of how to draw district lines. He moved his mouse to the border between two congressional districts. A ledger on the top half of the screen showed that one of the districts, as currently configured, had about forty thousand more people than the other one. "The Supreme Court has said that the requirement of one man, one vote means that each district must have exactly-exactly-the same number of people," Persily explained. An early version of the Pennsylvania plan was rejected by the courts because the districts were just nineteen voters apart, in districts of about a half million people. Requirements for that sort of precision virtually mandate the use of computers for redistricting.
Persily zeroed in even more closely, and a little donkey popped up inside one of the census blocks. "That's where the local congressman lives, a Democrat," he explained. "We have little elephants for the Republican incumbents." The program seemed easy to use, justifying the boast, on the software company's Web site, that you could "start building plans thirty minutes after opening the box." Persily chuckled. "At a certain point, you admire the video-game appeal of all this.
"There used to be a theory that gerrymandering was self-regulating," Persily explained. "The idea was that the more greedy you are in maximizing the number of districts your party can control, the more likely it is that a small shift of votes will lead you to lose a lot of districts. But it's not self-regulating anymore. The software is too good, and the partisanship is too strong."
The effects of partisan gerrymandering go well beyond the protection of incumbents and the guarantee of continued Republican control. It has also changed the kind of people who win seats in Congress and the way they behave once they arrive. Jim Leach, a moderate Republican and fourteen-term congressman from Iowa, has watched the transformation. Leach agrees with Richard Pildes on the numbers: "A little less than four hundred seats are totally safe, which means that there is competition between Democrats and Republicans only in about ten or fifteen percent of the seats.
"So the important question is who controls the safe seats," Leach said. "Currently, about a third of the over-all population is Democrat, a third is Republican, and a third is no party. If you ask yourself some mathematical questions, what is half of a third?- One-sixth. That's who decides the nominee in each district. But only a fourth participates in primaries. What is a fourth of a sixth? A twenty-fourth. So it's one twenty-fourth of the population that controls the seat in each party.
"Then you have to ask who are those people who vote in primaries," Leach went on. "They are the real partisans, the activists, on both sides. A district that is solidly Republican is a district that is more likely to go to the more conservative side of the Republican part of the Party for candidates and platforms. Presidential candidates go to the left or the right in the primaries and then try to get back in the center. In House politics, if your district is solidly one party, your only challenge is from within that party, so you have every incentive for staying to the more extreme side of your party. If you are Republican in an all-Republican district, there is no reason to move to the center. You want to protect your base. You hear that in Congress all the time, in both parties -- 'We've got to appeal to our base.' It's much more likely that an incumbent will lose a primary than he will a general election. So redistricting has made Congress a more partisan, more polarized place. The American political system today is structurally geared against the center, which means that the great majority of Americans feel left out of the decision-making process."
Next » | "Today, the House and the Senate have precisely flipped roles. Senate races, which are not subject to redistricting, are decided by actual voters, who do indeed change their minds with some regularity."
This article originally appeared in The New Yorker magazine on December 8, 2003 and appears here with permission from the author.