[2] Duff graduated magna cum laude from the University of Kentucky Honors Program in 1975 with a degree in political science and philosophy, where he was Phi Beta Kappa.

[3] After studying at the University of Edinburgh in Scotland in 1974, he returned to the U.S. in 1975 and worked for four years as an aide in the chambers of Chief Justice Warren E.

In 1991, a large contingent of Clifford and Warnke lawyers and staff, including Duff, merged with the firm of Howrey and Simon,[6] where he practiced antitrust, commercial litigation, and international trade until 1996.

From July 2006 through September 15, 2011, Duff served as Director of the Administrative Office of the United States Courts.

He was named to the University of Kentucky Arts & Sciences Hall of Fame in 2012 and was given the Georgetown Entertainment and Media Law Achievement Award in 2012.

[citation needed] On November 4, 2014, it was announced by Chief Justice John Roberts that Duff would once again become Director of the Administrative Office of the United States Courts, effective January 1, 2015.