It’s a rule the Supreme Court created in Purcell v. Gonzalez (2006). It says:

Courts should avoid changing election rules close to an election because it might confuse voters.

This principle has been used to:

• block fixes to illegal maps
• freeze lower‑court rulings
• allow elections to proceed under maps already found to violate the Voting Rights Act

In other words:

If a map is illegal but the election is near, the Supreme Court often says: “Use the illegal map anyway — we’ll deal with it later.”

This is why you see Black districts eliminated or weakened right before elections, even when courts agree the maps are discriminatory.

me and AI … let me know if you think it’s not accurate and cite the source for the correction if needed