Pinal County Sheriff Paul Babeu built a reputation as a rising, conservative star by taking a hard-line stance against illegal immigration, attacking the Obama administration and appearing alongside Sen. John McCain in a 2010 re-election ad in which McCain urged federal officials to just "complete the danged fence."

But on Saturday, Babeu's conservative image took a beating as he was forced to acknowledge publicly that he is gay and was involved in a relationship with a Mexican immigrant who has said the sheriff threatened to have him deported if he revealed their relationship.

Babeu denies any wrongdoing and has vowed to continue his battle for the GOP nomination in an extremely conservative rural congressional district. He recognizes he is fighting an uphill battle, especially in a state where family values, as defined by a large evangelical Christian and Mormon population, often compete with fierce, anti-immigrant beliefs to define conservatism.

At a lengthy press conference, Babeu said he hoped voters wouldn't judge him for his sexuality and stick with him.

Babeu previously avoided a public stance on gay rights but came out in favor of them on Saturday.

"I can be a supporter and get out there and help articulate as we progress as a culture and a society, that there should be individual liberties and there should be individual freedoms," Babeu said. "For any other person to define somebody else's relationship and say it is not OK, that is not who we are as Americans."

Some political observers think his career could be over.

"There is no question that his budding congressional campaign is over," longtime Arizona Republican political consultant Sean Noble wrote on his blog. "Because it is a Republican primary in a conservative district, it's likely that the thing that hurts him the most is that he was in a gay relationship."

Others aren't sure it's the end, but they said there's no doubt he will be hurt.

"It obviously has implications for a congressional race. There's just no question about it," said Bruce Merrill, an Arizona State University political science professor emeritus and a longtime pollster. "I don't see how any reasonable person cannot think that this is going to hurt him, particularly with the constituency that he has built, which is a very evangelical, right-wing, family-oriented, conservative constituency."

Babeu's statement that he is gay came after a story in the Phoenix New Times, an alternative weekly magazine, that quoted a former lover as saying Babeu threatened his immigration status if he revealed their relationship.

Babeu denied claims he tried to threaten the man, a Mexican immigrant and a former campaign volunteer. The legal status of the man, identified only as Jose by the New Times and Babeu, was unclear. His lawyer said he was unavailable for comment but might be available in a few days.

Babeu made national headlines soon after his 2008 defeat of an incumbent in his rural county south of Phoenix by jumping on the anti-illegal-immigration bandwagon led by longtime Maricopa County Sheriff Joe Arpaio and berating the federal government for what he called inadequate efforts to fight human and drug smuggling. Then, in 2010, he was tapped by McCain to help champion his border security plan during McCain's re-election effort.

McCain, asked Sunday on ABC's "This Week" about Babeu, said he thought of him as a friend.

"I do not know the details, except what has been published in the media," he said. "And I'm sure there will be a thorough and complete investigation, if there is any allegation of wrongdoing. All I can say is that he also deserves the benefit, as every citizen does, of innocence until proven guilty. But I appreciate the support that he gave me in my campaign and always will."

Babeu has been something of an enigma since he appeared on the scene. He was elected to the City Council of his hometown of North Adams, Mass., at age 18 and came to Arizona shortly after losing an election for North Adams mayor in 2001.

He became a Chandler police officer and in November 2008 defeated a Democratic incumbent to become sheriff. Along the way, he served in the Army National Guard as both an enlisted man and an officer, retiring from the Arizona Guard as a major after serving stints in Iraq and along the U.S.-Mexico border.