Gerrymandering has a long history in US politics, but the limits remain unclear

The long history of gerrymandering, and the limits of what courts can do

The United States has repeatedly changed voting district boundaries for political advantage for generations, and the term “gerrymandering” itself is a reminder that the practice has been controversial for a long time. The phrase was coined more than 200 years ago as an unflattering way to describe how people in charge of drawing legislative districts could manipulate them to benefit their party.

In many states, the process is built around a decennial cycle. Legislatures redraw U.S. House districts after each census so that each district has about the same number of voters, with the maps typically subject to approval or veto by a governor depending on the state’s rules. But the AP description of the system notes that some states do allow redistricting more frequently than that once-a-decade rhythm.

When a political party controls the legislature and the governor’s office, or when it can override vetoes with a large legislative majority, the party can draw districts more effectively to its advantage. One common approach described in the reporting is to dilute an opposing party’s voters by spreading them among multiple districts. Another is to concentrate—“pack”—the opposing party’s voters into a smaller number of districts so the party in power wins more of the surrounding districts.

The word “gerrymandering” traces to 1812, when Massachusetts Gov. Elbridge Gerry signed legislation redrawing state Senate districts to benefit the Democratic-Republican Party. The term followed a newspaper illustration that likened an oddly shaped district to a salamander. Gerry later lost reelection as governor in 1812 but won election that same year as vice president to President James Madison.

A 2019 U.S. Supreme Court ruling has left a major question unresolved in federal courts: whether partisan gerrymandering violates the Constitution when it becomes extreme. In a case originating from North Carolina, Chief Justice John Roberts wrote that “The Constitution supplies no objective measure for assessing whether a districting map treats a political party fairly.” The court said partisan gerrymandering claims could continue to be decided in state courts under those states’ constitutions and laws, and some state courts, including the North Carolina Supreme Court, have ruled they likewise lack authority to decide such claims.

Even where maps are challenged, the legal landscape can make it hard to stop the practice in federal court, and incentives for map-making can grow quickly. The AP analysis says the urge to gerrymander can become stronger when more is at stake, such as in years when control of the U.S. House hangs on narrow margins.

After the 2024 elections produced a very slim Republican majority in the U.S. House, the AP reporting describes how President Donald Trump urged Republican officials in Texas to redraw congressional districts to their advantage ahead of the 2026 elections. It also describes Democrats who control California’s government countering by redrawing their congressional districts, a move that California voters ratified. AP said that gerrymandering in those two most populous states encouraged officials in other states to redraw House districts as well, seeking an edge for their parties.

Researchers and statisticians have also tried to quantify the advantage that may come from gerrymandering. The reporting cited how Republicans, who control redistricting in more states than Democrats, used 2010 census data to create a strong gerrymander, and how an AP analysis of that decade’s redistricting found Republicans enjoyed a greater political advantage in more states than either party had in the past 50 years. It also described Democrats responding after the 2020 census and pointed to an AP analysis of the 2024 elections showing a significant political tilt in one-third of states’ congressional districts as an indicator of potential gerrymandering.

At the same time, the AP analysis said the overall number of U.S. House seats won by Republicans and Democrats in those elections tracked closely with what would have been expected based on the share of the vote each party received across districts. That tension—between measured signs of tilt in individual districts and broader seat outcomes that align with statewide vote shares—reflects the complexity of assessing how much gerrymandering alone shapes election results.