Williams was a staffer for President Bill Clinton and political director of the Democratic National Committee. He has also worked at the Center for American Progress.His wife served as deputy chief of staff for President Barack Obama.
Williams ran in the 2012 election for the U.S. House to represent New York's 13th District. He sought the nomination on the Democratic ticket. He faced incumbent Charles Rangel, Adriano Espaillat, Craig Schley, and Joyce Johnson in the June 26 Democratic primary. Rangel won the primary.