"These rumors and character assassinations are disgusting, outrageous and sick," Bauer said Wednesday at a press conference. "They are trash-can politics at its worst."
By facing the media, Bauer hoped to suffocate gossip before it raised doubts among his core Christian conservative supporters.
"I wanted to hold this press conference to say unambiguously that my wife and I have been faithfully married for 27 years," Bauer said.
"I have not had any physical contact with anyone in my campaign or out of my campaign other than my wife," Bauer said.
Charlie Jarvis, Bauer's former national campaign chairman, said he had warned Bauer "in the clearest terms" that he was spending too much time with a female campaign aide and it created a bad appearance. Jarvis, who now works for rival candidate Steve Forbes, did not say Bauer and the aide had an affair.
The Forbes campaign was adamant that it had nothing to do with Jarvis' assertion.
Bauer stepped forward in response to a cryptic gossip item in the New York Daily News that asked: "What presidential candidate is praying that a former secretary doesn't go public with her claim that he's been having an affair with a twentysomething woman?"
After the piece ran, Bauer said he assumed he was the target.
Bauer denied that campaign staffers raised questions about a relationship with a female aide, or that it was a direct factor in the departure of several of his people in the last few months.
"No one in my campaign cited to me as a reason a suggestion that I am having an affair," Bauer said.
But Bauer added: "For five or six weeks this rumor has been all over town ... and I suspect that there are people who have left who just didn't want to deal with the rumor."
Jarvis, now an unpaid consultant to Forbes' campaign, said people did question the appropriateness of the relationship.
"People have confronted Gary about the appearance of impropriety," Jarvis said. "I did it a number of times. Personally, I warned him in the clearest terms."
But Jarvis made no specific allegations beyond Bauer's spending "hours and hours and hours behind closed doors with a young single woman."
Bauer defended himself against those allegations, saying that, like every presidential candidate, he meets privately with every member of his campaign staff behind closed doors. He said he thought he was being unfairly questioned about it.