Marc Goldberg joined Cornerstone in July 2023, expanding the firm's public affairs presence to New Hampshire and bringing 17 years of media and strategic communications experience to the Public Affairs team.

Previously, Marc served as chief of staff for the office of Sen. Maggie Hassan (D-NH) since 2016. In this role, he managed a team of nearly 50 staffers across the Senator's D.C. office, five state offices and subcommittee office through the Homeland Security and Governmental Affairs Committee. Before that, he also served as Sen. Hassan's campaign manager as well as her communications director when she was New Hampshire's governor. Other communications roles include press secretary for former Maryland Lt. Gov. Anthony Brown and communications director for former Rep. Suzanne Kosmas (D-FL).

Marc has also served as the independent expenditure director for the Democratic Senatorial Campaign Committee. In this role he focused on running paid-media efforts across the committee's targeted states and building teams of TV, digital and polling consultants for each state.

Marc holds a bachelor's degree in political science with a concentration of American politics and a minor in psychology from the University of Pennsylvania.