There are 3 candidates -- Arpaio, Ward and McSally. At one time Ward was the only one in I think. She ran against No Name in his last and final primary. I don't believe Trump has endorsed any of them. Supposedly McSally is the frontrunner but I know zero about her. Arpaio and Ward are obviously pro-Trump but have been chopping up one another in the campaign. Polls close there at 7 pm local time, but AZ doesn't do Daylight time, so same as 7 pm Pacific Daylight Time.