(Las Vegas) For much of his public career, Sen. John Ensign has appeared a model of the religious right. By this week, he had become just another politician diminished by scandal. Rattled, humbled and alone at the podium, Ensign acknowledged to reporters an extramarital affair, the sort of moral failing he’s criticized in the past.

The Nevada Republican once called on President Bill Clinton to resign, declaring “the truth must come out.” In October 2007, he was sharply critical of former Sen. Larry Craig, of Idaho, calling the Republican’s arrest in an airport bathroom sex sting “embarrassing for the Senate.”

His own admission Tuesday came at a time when the two-term Nevada Republican was building his national profile and assuming leadership in his party. He had recently traveled to Iowa, fueling speculation about his White House ambitions.

The senator has said the Republican Party was in need of new leadership. He hoped to be among the fresh faces, and he built his resume by serving as the GOP’s top Senate candidate recruiter in 2008 and as chairman of the Republican Policy Committee in the Senate, the fourth-ranking leadership post. On Wednesday, he resigned from the position on the policy committee.

For Nevadans, he was known as a polished pro-business Republican and well-spoken ally of the state’s religious conservatives. He was a member of Promise Keepers, a men’s Christian group that espoused devotion to family and marriage.

As such, he talked openly about his biological father’s failing, calling himself the child of a deadbeat dad who never “told me once he loved me.” At a “Fatherhood Summit” in Reno in 2004, Ensign – himself a father of three – said fathers have been the biggest letdown in society.

Ensign was adopted at age 15 by his mother’s second husband, a Las Vegas casino mogul. He went on to veterinary school, ran an animal clinic and worked the family business as a casino executive before entering politics.

Ensign’s political life was entwined with his religious beliefs. Once in Washington, he lived for a time with other Christian lawmakers who organized prayer breakfasts and Bible study. When in Las Vegas, he continued to attend an Evangelical church in Las Vegas with his wife, Darlene, who did not move to Washington with him.

Ensign has opposed abortion and gay marriage and backed school vouchers.

“He’s been a very reliable ally and outspoken on marriage issues, on life issues,” said Richard Ziser, a leading religious conservative in the state. “His religious beliefs were a very high identifier with conservatives.”

As a candidate for Senate in 1998, Ensign was critical of Clinton’s handling of his admission of infidelity. Clinton blamed “other people for his problems, and that’s when he lost me.”

“He did lie to the American people. But he never looked at us and said he was sorry,” Ensign said.

On Tuesday, the senator apologized for his affair.

Many Christian conservatives will see Ensign’s public admission as brave and necessary, Ziser said.

“Some will be more forgiving than others, of course,” he said. “But I think his apology will be viewed as sincere. There is nothing wrong with holding yourself to high standard, even if you fail.”

Political science professor Fred Lokken said he believes the timing of the infidelity revelations won’t necessarily hobble Ensign’s ambitions.

It could be a tremendous bombshell – just as similar revelations damaged the career of former president candidate John Edwards, he said.

But Nevada has a long history of forgiving the personal troubles of its politicians, he said. Just two years ago, U.S. Rep. Jim Gibbons was elected governor while he was under investigation for assaulting a cocktail waitress. Charges were never filed in the case.

“I really do think that Nevada has a different standard for its politicians than the rest of the country,” said Lokken, of Truckee-Meadows Community College.