Arizona voters are heading to the polls for a critical primary election day, with significant implications for both state and national politics. The Republican primary for the U.S. Senate seat, vacated by retiring Sen. Kyrsten Sinema, is a key focus, with Kari Lake leading the pack against opponents like Pinal County Sheriff Mark Lamb. Other crucial races include the competitive Democratic primary in AZ-01, where six candidates vie to challenge Republican incumbent Dave Schweikert, and the GOP primary in AZ-08, featuring a heated contest between Blake Masters and Abe Hamadeh. The results of these primaries will set the stage for November's general elections, potentially shaping the balance of power in Congress. Polls close at 7 p.m., with early and absentee ballots expected to be reported quickly, though final tallies may take until Thursday.