Sen. Ensign says he will resign on May 3

Ensign has admitted to having an affair with Cindy Hampton, a campaign aide and the wife of Ensign's former chief of staff, Doug Hampton. Investigators are looking into efforts by Ensign to assist the Hampton family by providing a nearly $100,000 payment to them, arranging lobbying work for Doug Hampton, and possibly meeting with Doug Hampton on a lobbying matter in violation of Senate rules