Nevada senator acknowledges affair

LAS VEGAS - Senator John Ensign of Nevada, a leading Republican mentioned as a potential presidential candidate, admitted yesterday that he had an extramarital affair with a woman who was a member of his campaign staff.

“Last year I had an affair. I violated the vows of my marriage,’’ Ensign said at a brief news conference in his home state. “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.’’