Prior to his appointment, Giffin practiced law as a senior partner in the firm of Long, Aldridge & Norman (now McKenna Long & Aldridge LLP). He has since returned to McKenna Long & Aldridge LLP, which has merged into Dentons LLP.[3] He eads the firm's US Public Policy and Regulation practice.[4] While on an ambassador's trip to Montreal he took in a Montreal Canadiens hockey game, where a Molson Ice was dumped on his head for his outward support of Bill Clinton. From 1975 to 1979, he was Legislative Director and Chief Counsel to U.S. Senator Sam Nunn in Washington, D.C.
He expressed confidence Hillary Clinton would become President of the United States of America in a November 8, 2016, interview with Canada's Business New Network (BNN), stating "I was there during the first Clinton Presidency and now we're about to have the second."[5]
Giffin sits on the boards of several Canadian companies including Canadian National Railway,[6] Canadian Imperial Bank of Commerce [7] and Transalta.[8]
