JACKSON, Miss.—In early October, Mississippi Democratic candidate for governor Brandon Presley crisscrossed Jackson, shaking hands and taking selfies as he courted residents in the nearly 83%-Black capital city. He needed Jacksonians to vote if he was to have any chance of defeating incumbent Republican Gov. Tate Reeves on Nov. 7, he told supporters.
“Tate Reeves and that bunch he runs around with at the governor’s mansion—they have it in their minds that folks are not going to vote … (that) p...