Tarnished Republican drops leadership post

WASHINGTON (Reuters) - In a new setback for the struggling Republican party, U.S. Senator John Ensign resigned from a party leadership post on Wednesday after admitting an affair with a female staffer.

"He's accepted responsibility for his actions and apologized to his family and constituents. He offered, and I accepted, his resignation as chairman of the (Senate Republican) Policy Committee," said Senate Republican Leader Mitch McConnell.

Ensign's resignation causes another headache for the Republican Party, which preaches "family values" and has been scrambling to rebuild in wake of losing the last two congressional elections and the White House in 2008.

Ensign, of Nevada, led failed efforts by Republicans to pick up seats in last year's Senate elections, which left Democrats in control of the chamber with 59 of the 99 filled Senate seats.

As chairman of the Policy Committee charged with analyzing pending legislation, Ensign held the fourth ranking post in Senate Republican leadership.

Ensign, 51, who is married and had been seen as a potential 2012 presidential contender, admitted he had an affair last year with a staffer whose husband also worked for him. The couple no longer work for the senator.

If Ensign decides to seek a third six-year term in the Senate, he would be up for election in 2012.

(Reporting by Thomas Ferraro, Editing by Sandra Maler)