Five states hold primaries Tuesday: Arizona, Kansas, Michigan, Missouri and Washington.
Arizona is one of the most closely watched states in the nation, with competitive primaries for U.S. Senate, U.S. House, governor, attorney general and secretary of state. Former President Donald Trump has endorsed a slate of election-denying Republican candidates.
Polls open in Arizona at 6 a.m. local time and close at 7 p.m. local time.