ATLANTA (AP) — Republican efforts questioning the outcome of the 2020 presidential race have led to voting system breaches that election security experts say pose a heightened risk to future elections.

Copies of the Dominion Voting Systems software used to manage elections — from designing ballots to configuring voting machines and tallying results — were distributed at an event this month in South Dakota organized by MyPillow CEO Mike Lindell, an ally of former President Donald Trump who has made unsubstantiated claims about last year's election.

"It's a game-changer in that the environment w...