Congressional Redistricting and Gerrymandering in 2025

Americans in all 50 states are represented by members of the U.S. House of Representatives. Under the Constitution, a state receives its number of House members according to its population. Each House member is elected from a state's defined, geographic district. A state maps out these districts in a process called redistricting. This process shapes how communities are represented. With the House of Representatives so narrowly divided, even small changes in the map of these districts can tip the balance of power in Washington. This dynamic has driven both Republicans and Democrats in Texas, California, and New York to squeeze maps to their advantage-raising the possibility of one party locking in control of the House for years.

How Redistricting Works

Because population determines a state's representation, redistricting must occur whenever a change of population-as indicated by the census-requires a change in the state's number of House members. By federal law, the total number of House members nationwide is capped at 435. These 435 members must be apportioned among the states according to state population in a zero-sum manner.

If a state gains or loses population, it could gain or lose a House member. One state's gain requires another state's loss. For example, the 2020 census indicated a growth in Florida's population; Florida received one new House member as a result. Texas received two new members. New York and California each lost a House member after 2020. To accommodate either the gain or loss of districts, these (and some other) states had to redraw their electoral maps, or redistrict, after 2020.

Why Redistricting is Controversial

The Supreme Court has subjected redistricting to certain constitutional limits. Every district within a state must have an equal population. A population shift within a state could require redistricting. Further, the Voting Rights Act limits the ability of a state to redistrict in a way that harms the ability of a racial group to elect a House member of its choice. Redistricting may not be done in a way that dilutes minority electoral power-an issue that is often litigated during the redistricting process.

The political party that controls a state's government after the census will control redistricting. It is to the advantage of that party to put a majority of "their" voters in as many districts as possible. Many, if not most, districts today are drawn in precisely this way, even if they otherwise make no geographic sense. This is known as gerrymandering-when a district is drawn in a way that, based on demographics, ensures the election of a certain party's candidate. In 2019, the Supreme Court ruled that partisan-motivated gerrymandering does not violate the Constitution. However, many people believe that party-motivated gerrymandering undermines democratic values and the power of minority voters. And, in many parts of the nation, partisan and racial motivations closely align.

With the current House of Representatives so closely divided between the two parties, every district matters for power in Washington. This creates the incentive for both Democratic and Republican-controlled states to gerrymander as much as possible. Republican leaders in Texas realized this year that they were giving Democrats five districts that, if redrawn, would likely elect Republicans instead. The Texas legislature redrew its map to make these five districts more Republican. This move has prompted Democratic states like California and New York to squeeze out their Republican districts. However, they had better be careful. There are many more Democratic districts in Republican states than vice versa. The result of this redistricting war could be a solid Republican hold on the House of Representatives for decades.

Dr. James Todd is associate professor of politics and chair of PBA's Department of Politics. He teaches American government and politics, political science research methods, and more. He regularly gives talks about U.S. politics, the Supreme Court, and constitutional law. Before joining PBA, he spent a decade practicing law.