Senate Ethics Committee chair Barbara Boxer, D-Calif., said on CNN Sunday that her committee has opened an ethics investigation into whether or not Sen. John Ensign, R-Nev., violated the chamber's rules of conduct.

"I can't discuss this with you, other than to say there is a preliminary investigation going on and we will look at all aspects of this case as we do whenever there's a case before us and try to get to the bottom of it as quickly as possible," Boxer said to CNN's John King, when he asked her whether or not Ensign may have acted improperly in trying to cover up an extramarital affair with a staffer that he later publicly acknowledged.

Further, the Washington Post wrote an editorial today noting that the Nevada senator may have broken lobbying ethics rules by ignoring revolving-door strictures that ban former senate senior staff members from directly lobbying their former boss and colleagues for one year. Apparantly Ensign's former aide, Douglas Hampton and Ensign "were aware of the restriction but chose to ignore it."

It's important that the ethics committee look into that allegation as I wrote a story (subscription) in this week's National Journal about how little actual enforcement there is of the lobbying rules.