Nevada Senator John Ensign, a 2012 GOP Presidential hopeful, has resigned his post as Chairman of the Republican Policy Committee, the fourth highest spot in the leadership, in the wake of his admission of an extramarital affair with a campaign staffer. Ensign, whose 2012 hopes are now probably dashed, admitted yesterday at a news conference that he had an affair with a former campaign staffer, who is also married.

“Last year I had an affair. I violated the vows of my marriage,” Ensign told reporters, refusing to take any questions. “It is the worst thing I have ever done in my life. If there was ever anything in my life that I could take back, this would be it.”

Ensign’s spokesman, Tory Mazzola, said the affair took place between December 2007 and August 2008 with a campaign staffer who was married to an employee in Ensign’s Senate office.

Ensign was considered a rising star in some conservative circles and was looked at as a possible 2012 nominee to challenge Obama. The Senator made a recent trip to the birthplace of all presidential campaigns, Iowa.

Earlier this month, he went to Iowa, home to the nation’s first presidential precinct caucuses, to speak as part of a conservative lecture series designed to define the Republican Party after its shattering defeat in last year’s elections. Aides said the visit was about staking out a leadership position within the Republican Party.

At least Ensign dealt with this in the right way: he admitted to the affair, apologized publicly, and resigned his leadership post. You could never ask that much from the other side of the partisan divide. And of course, since it involves a Republican and sex, one ought to expect this scandal will get more attention than the work of Chris Dodd, John Murtha, Dick Durbin, John Conyers, or certainly Kwame Kilpatrick.