Q&A: Why is partisan gerrymandering OK under US Constitution

June 28, 2019 GMT

The U.S. Supreme Court ruled that federal courts have no authority to decide cases claiming that partisan gerrymandering of legislative districts violates the Constitution. The ruling Thursday could have implications for numerous states when they undertake the next round of redistricting after the 2020 census.


Q: What is redistricting?

A: The U.S. Constitution requires each state’s representation in the U.S. House to be adjusted based on the U.S. census every 10 years. States also use the census to redraw boundaries for their state House and Senate districts. The next census is in 2020, meaning most states will undertake redistricting in 2021.


Q: Who draws the legislative maps?

A: In many states, the state legislature is responsible for drawing new districts, subject to the approval or veto of the governor. But some states have entrusted redistricting to special commissions composed of citizens or a bipartisan panel of politicians.

Q: What criteria are used for redistricting?

A: The U.S. Constitution requires that each district have about the same number of people. The federal Voting Rights Act also requires that district boundaries allow minority voters an equal opportunity to elect representatives of their choice. Some states have adopted additional criteria, such as requiring districts to encompass compact, contiguous areas or to keep counties, cities and communities of interest together whenever possible.

Q: What is gerrymandering?

A: Gerrymandering occurs when district lines are drawn to give an advantage to a political party or group of people. One common method is for a majority party to pack voters who support the opposing party into a few districts, allowing the majority party to win a greater number of surrounding districts. Another common method is for the majority party to dilute the power of an opposing party’s voters by spreading them among multiple districts.

Q: Why is it called gerrymandering?

A: The term dates to 1812, when Massachusetts Gov. Elbridge Gerry signed a bill redrawing state Senate districts to benefit the Democratic-Republican Party. Some thought an oddly shaped district looked a salamander. A newspaper illustration dubbed it “The Gerry-mander” — a term that later came to describe any district drawn for political advantage. Gerry lost re-election as governor in 1812 but won election that same year as vice president with President James Madison.

Q: Is political gerrymandering illegal?


A: Not under the U.S. Constitution. The U.S. Supreme Court, in a 5-4 ruling, said that federal courts have no authority to decide whether partisan gerrymandering goes too far. Chief Justice John Roberts wrote: “The Constitution supplies no objective measure for assessing whether a districting map treats a political party fairly.”

Q: What is the immediate effect of the ruling?

A: The Supreme Court overturned lower court decisions saying that Republican lawmakers in North Carolina and Democratic officials in Maryland had illegally drawn congressional districts to benefit their political party. The high court ordered those lawsuits dismissed. The ruling also will likely lead to the dismissal of similar partisan gerrymandering cases in Michigan, Ohio and Wisconsin.

Q: Does this spell the end of all partisan gerrymandering lawsuits?

A: No. The Supreme Court noted that partisan gerrymandering claims can continue to be decided in state courts under their own constitutions and laws. In fact, a trial is scheduled to begin in mid-July in a North Carolina court alleging that partisan gerrymandering of state legislative districts violates the North Carolina Constitution. That comes after the Pennsylvania Supreme Court ruled last year that the state’s congressional districts were an illegal partisan gerrymander under that state’s constitution.

Q: What about other lawsuits related to redistricting?

A: The Supreme Court noted that federal courts can continue to decide cases alleging racial gerrymandering. Several of those cases are awaiting trials in Alabama, Georgia and Louisiana. Federal courts also can continue to hear lawsuits alleging violations of the one-person, one-vote principle.

Q: How can partisan gerrymandering affect elections?

A: By creatively dividing districts, partisan gerrymandering can allow a majority party to win more seats than otherwise would be expected based on the total votes cast for its candidates. In some states, gerrymandering has allowed one party to win a majority in a legislative chamber even though the other party got more overall votes.

Q: What does data show about gerrymandering?

A: Statisticians and political scientists have developed a variety of ways to try to quantify the partisan advantage that may be attributable to gerrymandering. The Associated Press analyzed the 2018 elections using one of those tests. It found that Republicans won about 16 more U.S. House seats than would have been expected based on their average share of the vote in congressional districts across the country. In state House elections, the AP’s analysis found that Republicans’ structural advantage may have helped them hold on to as many as seven chambers that otherwise could have flipped to Democrats.