Marshall worked in the Clinton administration from 1997 as assistant to the president and White House Cabinet Secretary. In that role, he managed White House relations with the executive departments; his responsibilities included organizing cabinet meetings and briefings, compiling a daily update of cabinet department activities, and coordinating responses to natural and transportation disasters. As vice-chair of the White House Olympic Task Force, he coordinated federal government's preparations for the 2002 Salt Lake City Winter Olympic and Paralympic Games. He was also a member of the Interagency Task Force on U.S. Coast Guard Roles and Missions.