He was neither. Duke was a one-term State representative in Louisiana. Despite his notorious baggage, he did not put forward any proposed legislation which was offensive. Of course, if memory serves, virtually everything that he *did* touch was voted down, regardless of the merit of the proposal. Republicans and Democrats alike sent him an immediate and continuous message that he was not welcome as a legislator.
Hey... maybe the source has the name wrong. Perhaps they're thinking of Senator Byrd.