Des Moines Register: Iowans will head to the ballot box today, casting the final votes in primary elections that will determine matchups in key races across the state, from Congress to the Statehouse. A trio of Democrats are vying for the chance to run for the U.S. Senate, campaigning on issues like abortion, gun violence and voting rights. Three Republicans are fighting for their party’s nomination in Iowa’s 3rd Congressional District, arguing over who’s best to take on Democrat Cindy Axne.