First came passage of one of the nation’s most restrictive voting bills. Then came efforts to overhaul the number of elected offices in one of Georgia’s largest counties. Now, with the pending passage of a new congressional map, Republicans have taken another step toward dismantling the Atlanta-area engine that turned Georgia blue, powering President Joe Biden to victory in 2020 and flipping control of the Senate to Democrats. Just as Georgia has emerged as a pivotal swing state, the GOP-controlled legislature has gone to extraordinary lengths to overhaul election administration, rewrite election rules and redraw political lines in the fast-growing...