Guiding Principles of Redistricting   

• Authority: State legislatures and commissions tasked with redistricting must redraw electoral districts that elect representatives to legislative bodies, typically single-member districts, every ten years following the federal decennial census. This redrawing is necessary to comply with the principle of “one-person, one-vote” by ensuring that districts are substantially equal in population. States may also engage in mid-decade redistricting, either voluntarily or pursuant to a court order.   
• Compliance with federal law: States must comply with federal law when redistricting. The U.S. Constitution requires districts to be equal in population and prohibits racial gerrymandering, intentional vote dilution and discrimination. As the Supreme Court of the United States recently opined, race-based redistricting is rarely if ever permissible. See Louisiana v. Callais, 146 S.Ct. 1131 (2026). States therefore should not consider race when redistricting. Federal law does not prohibit map drawers from considering and implementing political, incumbency, and partisan objectives.   
• Compliance with state law: State redistricting authorities must also comply with state law when redistricting. Some state constitutions mandate adherence to traditional redistricting criteria, such as compactness, contiguity, and respect for political subdivision lines. Some states have enacted their own Voting Rights Acts which will undergo renewed scrutiny following Callais. Map drawers in those states should therefore first consult legal counsel before considering race in redistricting to comply with applicable state VRAs. Somes states also prohibit the use of partisan considerations or require that certain partisan fairness metrics be satisfied. States should consider reviewing state laws ahead of redistricting to ensure compliance with current federal rules and Supreme Court rulings.  
• Adoption and application of criteria: State redistricting authorities may choose to adopt criteria to guide the drawing of a proposed redistricting plan. Although not legally mandated, redistricting criteria can help refute allegations that impermissible criteria (such as race or politics, in some states) entered the process or that new race-based districts should be created. Districts should be compact, contiguous, and avoid splitting counties or municipalities. Other criteria could include: preserving communities of interest, core retention, and incumbency protection and partisanship.   
• Process: Redistricting plans are typically enacted by states through legislation. States should follow the applicable legislative processes for such legislation, at a minimum. State redistricting authorities should consider providing opportunities for obtaining public input on proposed redistricting plans and holding public hearings and debate on those plans. In states where commissions are charged with redistricting, it is equally important for the commissions to follow the enumerated processes and provide opportunities for public input and hearings, which are often legally mandated.      
• Data: Federal decennial census data from the U.S. Census Bureau should be used to conduct redistricting. States should ensure they have accurate and reliable data.   
• Experts and Legal Counsel: It is imperative that state legislators retain experts and experienced legal counsel to assist analyzing a proposed plan’s compliance with federal and state law.