Protesters in front of the Supreme Court while the justices hear arguments on gerrymandering, on Oct. 3, 2017, in Washington, D.C. (Bill O'Leary/The Washington Post)

Majorities of voters in at least three battleground states — Pennsylvania, Michigan and North Carolina — chose a Democrat to represent them in the state’s House of Representatives. Yet in all three states, Republicans maintained majority control over the chamber despite winning only a minority of votes.

For that, you can thank gerrymandering — the process by which partisan lawmakers draw legislative districts in a way to disadvantage their opponents. Its effects are well-documented at the federal level: In states like North Carolina, U.S. House delegations feature huge Republican majorities, even when the majority of voters choose a Democratic representative.

But gerrymandering is just as much of an issue at the state government level, as the cases of Pennsylvania, Michigan and North Carolina illustrate.


(Illustration by Christopher Ingraham for the Washington Post)

In Pennsylvania, Democratic candidates won 54 percent of the statewide House popular vote, but they walked away with 92 seats in the 203-seat state legislature, or 45 percent. This disparity is largely due to how the districts were drawn. Pennsylvania is unique, in that its state legislative districts are drawn by a commission consisting of the majority and minority leaders of the state House and Senate, as well as a commission chair typically appointed by the state Supreme Court.

Pennsylvania’s Supreme Court happens to be a partisan institution, with Democratic and Republican judges vying for election to 10-year terms. Whichever party controls the Supreme Court, then, controls redistricting. In 2011, when state legislative districts were drawn following the 2010 Census, the Pennsylvania Supreme Court happened to have a majority of conservatives on its bench. In 2011 the Court appointed Stephen J. McEwen Jr., a well-respected conservative judge who unsuccessfully ran for Congress as a Republican in 1974, to serve as the commission’s chairman.

The maps drawn up by that commission remain in effect this year, ensuring Republicans hold on to the House majority despite losing the statewide popular vote by more than 370,000 ballots.

Michigan and North Carolina are more straightforward cases. The states draw their legislative districts by passing bills in the legislature. Whichever party controls the legislature controls the redistricting, and Republicans happened to be in charge of both legislatures following the 2010 Census.

In 2018, both states saw a six percentage-point gap between Democrats' share of the popular vote, and the share of state House seats they won. Michigan Democrats won 200,000 more votes statewide than Republicans did but will get 52 out of 110 seats. North Carolina Democrats prevailed in the popular vote by 79,000 votes but won 54 out of 120 seats.

Democrats have been known to indulge in the occasional gerrymander when they’re in power, as the case of Maryland so vividly illustrates. Yet in the run-up to the 2010 Census, it was Republicans who realized that the pathway to power ran through the nation’s statehouses, where most districts are drawn. They weren’t exactly subtle about this — their redistricting initiative had a name (REDMAP), and a public website where, in 2013, they boasted that “Republicans enjoy a 33-seat margin in the U.S. House … having endured Democratic successes atop the ticket and over one million more votes cast for Democratic House candidates than Republicans.”

Redistricting is coming up again in 2020, and this time around, Democrats appear determined not to be caught flat-footed. A group formed by former attorney general Eric H. Holder Jr. is working to put Democrats in charge of state legislatures, an effort that’s already borne some fruit.

Meanwhile, one unintended consequence of Republicans' 2010 successes is increased public awareness of gerrymandering and the ways in which it skews representative democracy. To that end, voters have been busy approving ballot measures that take redistricting control out of the hands of lawmakers entirely.