In one state and for one candidate, the 2018 midterm election isn’t over.

Georgia Democratic gubernatorial hopeful Stacey Abrams lost to Republican Brian Kemp by 54,723 votes, 50.2% to 48.8%. Turnout was 3.9 million, the biggest ever in a Peach State governor’s race.

But Ms. Abrams insists she “cannot concede” that the outcome “is right,...