Gerrymandering, the process of drawing district lines to fortify one political party at the expense of another, is as old as the U.S. republic. In the late 1780s, Virginia Governor Patrick Henry, who opposed ratifying the new Constitution, got allies in his state’s legislature to draw a congressional district map unfavorable to James Madison, the father of the founding document. (Madison won anyway.) Good-government groups grouse that gerrymandering lets politicians choose their constituents, rather than the other way around. But as the courts get more involved, others fret about judges interfering in politics.
1. Why is redistricting necessary in the first place?
The nation’s 435 House districts are adjusted after each decennial census. The goal, as required by the U.S. Supreme Court, is to make sure that, in states with more than one House member, the congressional districts have roughly the same number of people. (State legislative districts are redrawn as well.) Gerrymandering can result in districts being comically shaped to get the right number of people and the hoped-for political breakdown. One district in Pennsylvania is said by critics to resemble the cartoon character Goofy kicking Donald Duck.
2. How exactly does gerrymandering work?
There are two primary tactics that governing Party A can use to limit the number of congressional seats Party B can win. One is called "packing," or cramming many of Party B’s voters into a few districts that it will win overwhelmingly, with many (wasted) votes to spare. The other technique, "cracking," splinters Party B’s voters among multiple districts so that it can’t prevail in any of them. Using such techniques, a party can turn a narrow lead in statewide voters into a decisive and lasting advantage in a state’s congressional delegation. In North Carolina, for instance, House Republicans in 2016 won 10 of the 13 seats with just 53 percent of the popular vote. Better technology, and more-detailed information about voter preferences, have made gerrymandering an even more potent tool.
3. Who draws these crazy-looking districts?
That varies by state. Traditionally the task has been left to the state legislatures and governors, which means the party that controls two branches of state government can steer the direction of elections for a decade. To counter the influence of politics, six states -- Arizona, California, Hawaii, Idaho, New Jersey and Washington -- have shifted redistricting responsibility to an independent or bipartisan board or commission; Iowa empowers a nonpartisan state legislative agency to draw district lines without taking political data into consideration. Wisconsin and Maryland, whose redistricting plans are being challenged before the Supreme Court, are among the states that still leave the task to elected state legislators.
4. What’s the problem with gerrymandering?
One frequent criticism is that, by making many congressional districts safely Democratic or Republican, gerrymandering undermines the competitiveness of federal elections and serves the interests of hyper-partisan candidates, thus contributing to political polarization and gridlock.
5. Why is the Supreme Court involved?
Although the court has grappled with racial gerrymandering claims for decades, it’s never struck down an electoral map as unconstitutionally partisan. In 2004, the court upheld a Republican-friendly congressional map in Pennsylvania in a 5-4 ruling that showed a majority of justices were open to evaluating gerrymandering, if only a workable test could be devised. That’s the burden facing those challenging Wisconsin’s Republican-friendly state legislative map, who say they’ve come up with a workable standard that centers on the principle of "partisan symmetry" -- the idea that each party should win roughly the same number of seats given the same percentage of the overall vote. The Maryland case is narrower, focusing on a single congressional district that Republicans say was drawn to oust one of their House members.
6. Why has this been a tough issue for the court?
Determining when district lines are too partisan isn’t cut-and-dried. Election outcomes depend on factors other than how district lines are drawn, including the strength of candidates’ campaigns, the institutional advantages of incumbency and population shifts. In Wisconsin, for instance, Republicans say the proposed "efficiency gap" measure won’t properly account for the state’s natural political geography, which packs Democratic super-majorities in Milwaukee, Madison and smaller industrial areas, while Republican voters are more spread out.
7. Will Supreme Court rulings affect this year’s elections?
It’s almost certainly too late for that. But in Maryland and North Carolina, legal challenges are far enough along that they could affect the 2020 House elections. And any broader rules set by the Supreme Court would shape the congressional lines redrawn after the 2020 census, for the 2022 election and beyond.
8. Have courts overruled gerrymandered maps before?
Though the U.S. Supreme Court hasn’t, other courts have. Just this year, Pennsylvania’s Supreme Court invalidated a Republican congressional map under which that party won 13 of 18 congressional districts in the elections of 2012, 2014 and 2016 -- this in a state about evenly divided between Democrats and Republicans. The Pennsylvania court, acting on the basis of the state constitution, implemented its own map for the 2018 election, one that created more-compact districts less friendly to Republicans.
9. Can anything else be done about gerrymandering?
Article I, Section 4 of the Constitution grants Congress the power to regulate federal elections. But lawmakers have been loath to shift map-drawing power away from state legislatures. Four House Democrats have proposed legislation that, in part, would limit redistricting to once per decade and require independent state commissions to redraw lines.
10. Why is it called gerrymandering, anyway?
In 1812, Massachusetts Governor Elbridge Gerry signed into law a state redistricting plan to favor his party over the opposition. A Boston newspaper cartoon depicted one of the districts as a salamander and invoked the amalgam "Gerry-mander," etching it into the political vernacular for more than two centuries.
The Reference Shelf
- Brennan Center for Justice backgrounders and links to legal briefs for the Wisconsin case, Gill v. Whitford, and the Maryland case, Benisek v. Lamone.
- A Congressional Research Service report on redistricting.
- More about the 2004 Supreme Court case on Pennsylvania’s map.
- There’s already a fight over the 2020 census.
- The Library of Congress recalls "Elbridge Gerry and the Monstrous Gerrymander."
— With assistance by Greg Stohr, and Anne Cronin