Republican Jeff Flake and Democrat Richard Carmona are competing for the U.S. Senate vacated by retiring Sen. Jon Kyl.
Flake is a six-term congressman.
Carmona was surgeon general under President George W. Bush.
In a tight race, Flake ran an ad in which an ex-boss of Carmona says he has personality shortcomings related to anger, ethics and women.
Carmona countered Flake's ad, presenting favorable testimonials both on-air and in-person from women whom he's worked with and for.
Carmona denied the former boss' years-old accusation that he went to her home at night and angrily pounded on her door.
Flake's campaign responded by releasing a statement in which a former colleague of the ex-boss vouches for her honesty.
Libertarian Marc Victor, a criminal defense lawyer who served in the U.S. Marines, is also in the race.
Stay with cbs5az.com and CBS 5 News for results on this race.
Copyright 2012 CBS 5 (Meredith Corporation). All rights reserved. The Associated Press contributed to this report.