LAS VEGAS — Nevada Sen. John Ensign, an emerging Republican leader who has been mentioned as a possible 2012 presidential candidate, apologized Tuesday for an extramarital affair with a former staff member but indicated that he had no plans to resign.
"It's absolutely the worst thing I have ever done in my life," he said at a televised news conference. "If there was ever anything that I could take back in my life, this would be it."
A grim-faced Ensign, 51, did not identify the woman he was involved with from December 2007 to August 2008, although he described her and her husband as close friends who had worked for him.
"That closeness put me into situations during a very difficult time in my marriage, which led to my inappropriate behavior," he said. "We caused deep pain to both families, and for that I am sorry."
He and his wife, Darlene, sought counseling, he said, and their marriage is "stronger than ever." She was not at the news conference but issued a statement supporting him. They have three children.
It was unclear why Ensign made the disclosure so abruptly. He skipped a Senate vote related to tourism, his state's lifeblood, and flew to Las Vegas for the hastily arranged news conference.
The silver-haired, telegenic conservative has been a rising star in the Republican Party. He is a regular on the cable news circuit, often criticizing President Obama's economic stimulus package. Ensign recently visited Iowa, where he chatted up locals, ate ice cream and fueled speculation that he was gearing up for a presidential bid.
He headed the GOP's Senate campaign panel in 2008, when the party lost at least eight seats. Now he chairs the Republican Policy Committee, a Senate leadership position.
Political experts speculated that Ensign's admission would do him little harm here. "He's the leading voice in Nevada and in the country for fiscal restraint," said Robert Uithoven, a Republican consultant based in the state.
But the revelations could derail his national ambitions, at least in the short term, by turning off values voters in the South and the Corn Belt, experts said.
"It's hard enough for someone in Nevada to run on the national stage because Nevada has such a libertarian streak that others don't understand," said Joseph M. Valenzano III, who teaches political communication at the University of Nevada, Las Vegas. "He didn't need this."