Judge Nelva Gonzales Ramos said that evidence "establishes that a discriminatory purpose was at least one of the substantial or motivating factors behind passage" of the measure.
Trump's fantasies are to urge tougher voter ID laws.
The Obama Justice Department filed cases to increase voting access for minorities, experts say, but a Trump DOJ might focus instead on voter fraud
Ken Livingstone said a need to show ID at the ballot box could deter voters.
Republican Governor Pat McCrory is fighting to try to make up ground against Democrat Roy Cooper.
California Governor Jerry Brown has registered to vote everyone with a driver's license.
State laws have the potential to reduce eligible voters' ability to cast ballots.
Democrats say voter fraud is rare and the rules are intended to deter voters.