Redistricting Criteria and Legal Requirements
All congressional, state legislative, and local district lines must comply with certain federal constitutional and statutory requirements, including provisions designed to ensure that districts represent an equal population and do not racially discriminate. State law governs the remaining requirements. While criteria vary from state to state, common criteria traditionally include the following.
Regardless of who is drawing the lines, all line drawers must comply with the districting rules created by the United States Constitution and federal law. Each state generally has their own rules when it comes to what a line drawer may or may not consider when drawing maps.