Convicted criminal and diehard Trump supporter Sheriff Joe Arpaio faces a tough battle in Arizona’s Republican senate primary.
The Arizona congressman will likely bedevil Republican leaders for another term.
Some voters waited up to five hours to cast their ballot.
Some voters waited five hours to cast their ballot during the state's primary last month.
"I finally find somebody I want to vote for, and they deny me."
Though polls closed at 7 p.m., the last vote didn't come in until after midnight.
Clinton also won Arizona's 2008 Democratic primary.
He collects 58 delegates in the winner-take-all contest.
Hillary Clinton is also looking to extend her lead over Bernie Sanders.
She said criticism from Clinton's camp "has been consistently distorted."