Redistricting Maps and Gerrymandering

Redistricting Maps and Gerrymandering

Joan Schwarz

Schwarz is a retired attorney, University of Wisconsin—Whitewater faculty in the Department of Languages and Literature and Gender Studies, LWV Dane County member, and legal counsel and education leader for Wisconsin United to Amend (working on the 28th Amendment to overturn Citizens United to get money out of politics)

The Constitution mandates decennial reapportionment and redistricting of congressional and state legislative districts to reflect population shifts. Legislatures consider factors like compactness, the principle of one-person-one-vote, geographic boundaries, county and city lines and communities of interest in making these decisions.

History of Partisan Gerrymandering


Gerrymandering is as old as the republic. Even before Massachusetts governor Elbridge Gerry lent it his name to the process in 1812, politicians were playing games with maps. Patrick Henry tried to kill James Madison’s congressional career by carving him out of a House seat in the First Congress. He failed. Governor Gerry’s party was more successful. The Democratic-Republicans won 29 of 40 seats in the state legislature after redistricting. Gerry’s own district was so oddly shaped, it resembled a salamander. A cartoon published by The Boston Gazette dubbed it “The Gerry-Mander,” hence the name of gerrymandering.

Now before the United States Supreme Court are two partisan gerrymandering cases, one with a Republican gerrymandered map (Gill v. Whitford) and a Democratic gerrymandered map (Benisek v. Lamone). Chief Justice John G. Roberts, Jr. had worried aloud during arguments in Gill v. Whitford that hearing this case would cause “very serious harm” to the Supreme Court’s “status and integrity” if people perceived the court as intervening in a gerrymander case in order to favor one party over another. Now, with the Supreme Court weighing gerrymandered maps from the opposing parties, any partisan concerns and the possibility of even the appearance of partisanship may be muted.

Gill v. Whitford—Wisconsin’s Republican Partisan Redistricting Map

There is strong evidence that Wisconsin is a battleground with lots of healthy competition. Wisconsin swings in favor of Republicans some years and toward Democrats in other years, depending on the mood of voters. However, while the overall state is “purple” in its makeup, most legislative districts are “red.” Because Democratic voters are packed into fewer districts, the vast majority of seats are more Republican than the state as a whole.

Because of these skewed results, in the case Gill v. Whitford, a three-judge panel at the 7th Circuit Court of Appeals threw out Wisconsin’s 2011 redistricting map. While the plaintiffs are focusing on the lower house of the state legislature, the state senate district boundaries are implicitly involved in the case because they are based on the a ssembly districts. The Court of Appeals found the maps were not only excessively partisan, but were among the most heavily skewed to one party of any plan in the country in recent decades. At the 7th Circuit Court of Appeals, senior judge Kenneth Ripple, appointed by Republican President Ronald Reagan, wrote “it’s clear the drafters [the Republicans] got what they intended to get. There is no question [the legislative maps] were designed to make it more difficult for Democrats, compared to Republicans, to translate their votes into seats.” The Court of Appeals concluded that one of the goals of the GOP redistricting plan “was to secure Republican control of the Assembly under any likely future electoral scenario for the remainder of the decade, in other words to entrench the Republican Party in power.” The appellate court thereby ordered the state to redraw its maps by November 1, 2018. But the state appealed to the U.S. Supreme Court, which accepted the case and heard oral arguments in October 2017. So far, top GOP lawmakers have spent more than $2.1 million of Wisconsin taxpayer money on lawyers’ fees defending the maps. The Whitford decision is still pending.

Wisconsin—a Competitive State—Has a Map in Which Many Seats Skew Republican

This kind of gerrymandered map occurred when Democratic voters were highly concentrated or “packed” into fewer districts, giving the Democrats more votes than it needed in the districts it dominated, but fewer votes elsewhere. The result was a minority of seats that were lopsidedly Democratic and a majority of seats that had a smaller but decisive GOP edge. Another partisan measure called “cracking” means one party “cracks” their opponent’s supporters among many districts where their preferred candidates tend to lose by small margins.

This illustration of four methods used to create partisan a gerrymander comes from the glossary at Redistricting the Nation.

This illustration of four methods used to create partisan a gerrymander comes from the glossary at Redistricting the Nation.

Part of the GOP advantage in Wisconsin is natural because Democrats are more concentrated geographically in urban areas, such as Milwaukee and Madison, meaning their voters are less efficiently distributed across districts statewide. This effect was even more pronounced in November 2016 because the partisan gap between urban and rural Wisconsin was larger than usual.

But the federal court in Gill v. Whitford found that population patterns did not explain away the sheer magnitude of the partisan tilt in the Wisconsin maps. The result of this “tilt” is that whatever share of the vote the GOP wins in statewide races for president or governor, they are likely to win a much higher share of legislative seats.

The “tilt” is measurable by looking at a formula that calculates how many “wasted” votes a party has because its voters are concentrated in fewer districts. A simple way to illustrate this “tilt” or lopsidedness is to use the presidential and gubernatorial vote as a measure of how each district compared in its partisan makeup to the state as a whole. Examples of elections illustrate this “tilt”:

In the presidential election of November 2016 between Trump and Clinton, Trump won statewide by 0.76 of a percentage point, but the GOP won 64% of the Assembly seats, meaning those districts were more Republican than the state as a whole. Thus, while the state as a whole was ultracompetitive in 2016—decided by less than a percentage point in the presidential vote—hardly any of the state’s 132 legislative districts reflected that overall partisan balance.

In the presidential election of November 2012 between Obama and Romney, Republicans got only 46% of the presidential votes, but they still won 60% of the Assembly seats.

In the gubernatorial election of November 2014, Republicans got just over 52% of the vote for governor, but captured 63% of the Assembly seats.

Thus, under the present districting map, if 60 or more Assembly seats are redder than the state as a whole, and fewer than 40 are bluer than the state as a whole, then an election in which both parties get the same number of votes statewide typically results in at least a 20-seat GOP edge in that chamber. The result of the present map is that while Democrats can win many more votes statewide, they cannot win legislative control; conversely, while Republicans can have a “down” year (as they did in 2012), they can win a majority of the state’s voters and easily retain control.

In other words, in a state in which three of the past five presidential races have been decided by less than a percentage point, only a small handful of legislative seats are balanced in their partisan make-up. The rest are virtually locked in for the party that currently holds them. And in the clear majority of cases, that means the Republican Party.

The data shows that for Democrats to win just a bare 50-seat majority in the Assembly under the current districting lines, they would have to capture at least 14 seats that voted for Trump in 2016, and 9 that voted for both Trump in 2016 and Romney in 2012. In some of those seats, the built-in GOP advantage is not just a point or two, but 5 to 10 points.

The Democratic Plaintiff’s Legal Argument in Gill v. Whitford

In an earlier gerrymandering case, Vieth v. Jubelirer, the Supreme Court voted 5-4 not to intervene. Justice Kennedy agreed with the majority that the Supreme Court should not intervene in partisan gerrymandering cases because it did not have adequate tools to do so, stating in a concurrence that “the failings of the many proposed standards for measuring the burden a gerrymander imposes on representational rights make our intervention improper.” He added that “if workable standards do emerge to measure these burdens, however, courts should be prepared to order relief.”

Enter the plaintiffs in Gill v. Whitford. Based on Justice Kennedy’s reference to “workable standards,” the plaintiffs in Whitford created a new metric referred to as the “efficiency gap” that measures the difference in a state between the number of votes cast in favor of a party candidate and the number of seats won by that party. In the examples cited above, the differences between the actual votes cast statewide versus the larger percentage of the chamber’s seats awarded are referred to as “wasted votes,” with the difference being referred to as “the efficiency gap.” The Supreme Court is being asked to analyze the underlying demographic shifts as well as consider possible district cracking in Wisconsin using this metric. Under this metric, the balance of seats in each of Wisconsin’s two state-level legislative bodies and its eight seats in the U.S. House of Representatives should be roughly equivalent to the partisan balance of votes statewide—regardless of demographic processes.

Efficiency Gaps for House Plans by State, 2012   [From The New Republic, "Here's How We Can End Gerrymandering Once and for All" by Nicholas Stephanopoulos, July 2, 2014]  Chart includes only House district plans with at least eight districts. Efficiency gap is measured in seats for greater comparability. Plans in red were challenged on gerrymandering grounds. Horizontal lines show range of values that efficiency gap could take given plausible swings in parties' performances.

Efficiency Gaps for House Plans by State, 2012   [From The New Republic, "Here's How We Can End Gerrymandering Once and for All" by Nicholas Stephanopoulos, July 2, 2014]

Chart includes only House district plans with at least eight districts. Efficiency gap is measured in seats for greater comparability. Plans in red were challenged on gerrymandering grounds. Horizontal lines show range of values that efficiency gap could take given plausible swings in parties' performances.

[You can hear the arguments in Gill v. Whitford in a video linked at the end of this article.]

Benisek v. LamoneMaryland’s Democratic Partisan Redistricting Map

Also being considered by the U.S. Supreme Court is the case of another gerrymandered map, this one gerrymandered by Democrats. In this case, a special three-judge federal district court voted 2 to 1 to reject the plaintiff’s (Republicans) request for an order requiring new district lines to be in place for the 2018 midterm election. This case focuses on gerrymandering in one district—the Sixth District in Maryland. A week later, the plaintiffs appealed to the Supreme Court, with a motion to expedite consideration of the case so that it could be heard in November, just weeks after the argument already scheduled in Whitford. When the justices denied that request without comment on September 12, 2017, the natural assumption was that the court would simply keep the Maryland case on hold until it decided the Wisconsin case later in the term. But then the Supreme Court decided to take the Lamone case.

There are significant legal differences between Gill v. Whitford and Benisek v. Lamone. In Whitford, Democrats have brought their case under the guarantee of the Equal Protection Clause of the 14th Amendment and challenged the Assembly districting as a whole, rather than focusing on particular districts.

A little historical background about gerrymandering cases is in order. In previous election law precedents, based on earlier racially discriminatory election practices, the Supreme Court has not favored statewide challenges based on equal protection violations in particular districts. In Vieth v. Jubelirer 14 years ago, the Supreme Court rejected (5 to 4) a challenge to a Republican gerrymander of Pennsylvania’s congressional districts, stating that the federal courts lacked jurisdiction to review a political gerrymander. In Jubelirer, Justice Kennedy wrote in a separate opinion that “where it is alleged that a gerrymander had the purpose and effect of imposing burdens on a disfavored party and its voters, the First Amendment regarding political association may offer a sounder and more prudential basis for intervention than does the Equal Protection Clause.”

In keeping with this view about partisan gerrymandering cases being brought under the First Amendment, Justice Kennedy questioned the plaintiffs in Whitford about whether they had “standing” to bring the case, since they sued under the Equal Protection Clause of the 14th Amendment. “Standing” is a threshold issue in a case which questions whether the plaintiffs have a legally cognizable interest in the matter. This issue—whether a partisan gerrymandering case is best filed under the First Amendment as in Jubelirer or under the Equal Protection Clause of the 14th Amendment as in Whitford—may be the determining factor in the Supreme Court decisions in the Wisconsin and Maryland cases, since Justice Kennedy is the swing or pivotal judge whose vote will probably be decisive in both cases.

Hence, the plaintiffs in the Lamone case are trying to avoid the possible standing issue by bringing their case under the First Amendment to attack the Democratically gerrymandered map in Maryland. In their petition before the Supreme Court, the Republican voters argued that the Democratically controlled legislature and Maryland governor “targeted them [the Republicans] for vote dilution because of their past support for Republican candidates for public office, violating the First Amendment retaliation doctrine.” The plaintiffs further argued that “the map-drawers reshuffled fully half of the district’s 720,000 residents—far more than necessary to correct the mere 10,000-person imbalance in the district’s population following the 2010 census.” As a result, the “registered Republicans’ share of the electorate fell from 47% to 33%.” The Supreme Court is scheduled to hear oral arguments in the Maryland case in March 2018.

The results in these two cases are important to the future of redistricting throughout the country. With redistricting maps that are gerrymandered by both the Republicans and Democrats, the U.S. Supreme Court has an opportunity to weigh in on the issue of partisan gerrymandering, a position that it has avoided in the past. By agreeing to deliberate and decide two opposing partisan gerrymandered maps, the Supreme Court can adopt a nonpartisan process for drawing legislative and congressional districts. Certainly in Wisconsin, it is what voters want, as demonstrated by an overwhelming vote in favor of such a process by the Wisconsin Counties Legislation Association, which represented partisans from every part of the state. The time is now more than ripe to restore fairness to our electoral process.

[CORRECTIONS: Since publication, errors in identification of Maryland as Massachusetts were corrected.]


The SCOTUS does not allow cameras in the courtroom during oral arguments so if you want to see what happens during a Supreme Court case you have to make the video yourself. IN THE SUPREME COURT OF THE UNITED STATES Beverly R. Gill, et al., Appellants v. William Whitford, et al., Appellees.

Bill Whitford will be the speaker at our April Issues Forum (April 11, 2018) on Fair Voting Maps.

You may also be interested in reviewing our March 2016 forum on Redistricting, which has an audiopodcast.

District maps courtesy of David Michael Miller, from the Isthmus article, Slaying the Gerrymander, February 6, 2014.