Illegal voting maps were used in some states in 2022. This legal idea allowed them

(Mariam Zuhaib/AP)

Mariam Zuhaib / Mariam Zuhaib

A closely watched U.S. Supreme Court ruling last month confirmed that Alabama voters cast ballots in illegally drawn voting districts for Congress in the 2022 elections.

There’s an obscure legal idea behind why the court allowed it to happen. It’s known as the “Purcell principle.”

To midterm voters in Alabama, its use by the Supreme Court meant that their ballots were cast in congressional districts that a lower federal court ruled — and the high court later confirmed — likely violated the Voting Rights Act as racial gerrymanders that dilute the power of Black voters.