• Redistricting 101

How Redistricting Works

Design: Reed Dudley, © National Democratic Redistricting Committee

Redistricting in the Constitution

Under Article I, Section 2 of the U.S. Constitution, the federal government is required to conduct a census of the entire population every ten years. Once the U.S. Census is complete, the U.S. Census Bureau releases  the results to determine how many congressional districts (and, therefore, electoral college votes) each state will have for the next decade. This process is called apportionment. 

From there, each state must redraw its congressional and legislative district boundaries to reflect population changes. This process, known as redistricting, is intended to ensure that each district has the same number of residents, upholding the principle of “one person, one vote.” 

States vary in how they conduct redistricting: some assign the responsibility to the state legislature, others use independent redistricting committees. While the specific procedures differ, all redistricting must comply with federal law, including protections against racial discrimination, and follow criteria established in state constitutions, statutes, or procedural rules.

The Rules of Redistricting

All districts must have equal populations to ensure fair representation. This principle guarantees that each person’s vote carries similar weight across districts.

Who Draws the Maps?

As noted above, once the census data is released, each state must redraw its congressional and legislative district boundaries to reflect population changes. While the U.S. Constitution requires redistricting, it leaves the details of how redistricting happens up to the states.

Each state’s constitution outlines which body is in charge of redistricting, and may set additional requirements to those bodies. Many states have the state legislature draw the maps, while others have independent or non partisan commissions draw the maps. You can see who draws the maps in your state in our Who Draws The Lines resource guide. 

State statutes often go further, spelling out procedural details like how public hearings are conducted, how draft maps are shared, or how disputes are resolved.

The Role of the Courts

Courts play a major role in the redistricting process. In some states, courts are required by the state constitution to review maps before they take effect, ensuring that the maps meet Constitutional and legal standards.

In other states, courts step in when lawmakers or commissions can’t agree on new maps, sometimes drawing temporary or permanent maps so that elections can proceed on time.

Even after maps are finalized, they can be challenged in state or federal court – and even make their way to the Supreme Court – if the maps have violated the federal law and are putting constitutional rights at stake.

This means that voting rights cases in one state can quickly have national implications. A lawsuit about fair maps in Alabama or Louisiana can, within months, shape voting rights for millions across the country.

The Power of Direct Democracy

But the courts don’t always have the final say. In many states, voters can directly shape how redistricting works through ballot initiatives and measures.

Ballot measures can be used to create independent redistricting commissions, turn over gerrymandered maps, and strengthen fair mapping standards.

Public Input

Beyond the ballot box, voters can also shape the redistricting process by submitting public comments, testifying at redistricting hearings, and even proposing their own alternative maps in some states.

These opportunities give our communities a voice in how the lines that shape their lives are drawn, ensuring that our democracy reflects real people and places, not just political interests.

Why Redistricting Matters

Redistricting shapes everything we care about, from the schools our kids attend to the roads we drive on to the policies that affect our daily lives.

Fair districts ensure that every neighborhood has a voice and every voter has the power to shape their own future, ensuring that power flows from the ground up, not the top down.

We’re leading a powerful movement to build a democracy that works for everyone.