Two of Arizona's nine congressional districts are wide open this year, with voters in Tuesday's primary selecting party nominees to run in the general election.
All nine congressional seats are up for office. Five are currently held by Republicans. Two seats - the one held by Democratic. Rep. Kyrsten Sinema and the one held by Republican Rep. Martha McSally - have no incumbent running, since both are vying to replace retiring Sen. Jeff Flake.
Voters will decide scores of races across all levels of government.
The congressional races and their electoral breakdown will be of import to national politicos seeking clues on whether Democrats can take control of the U.S. House of Representatives in November.
Arizona voters are engaged: As of Monday, around 838,000 early ballots were already cast.