Mac joined Democracy Partners in 2012 after 11 years at the Service Employees International Union. 

Prior to joining SEIU, Mac led a legislative coalition based at Greater Boston Legal Services to address the negative impacts of welfare reform on low-income families.

During his career in politics, Mac has worked across the country, either on staff or as a consultant, for mayoral, congressional, and gubernatorial candidates.

In 2010, Mac was a candidate for United States Congress when he ran against an incumbent Democrat who was one of only 34 Democrats nationally to vote against the Affordable Care Act, the landmark national healthcare reform law. 

Despite no name recognition, no cash-on-hand, and a mere five months before the Democratic primary, Mac managed to raise $350,000, secure several prominent endorsements, including the Boston Globe's, and garner 36% of the vote.

Mac has had the privilege of working on two once-in-a-lifetime campaigns: Harold Washington's mayoral campaign in Chicago when he was 12 years old and Barack Obama's presidential campaign in 2008.

Currently, Mac is running a $2 million project for NARAL Pro-Choice America to mobilize around the Whole Woman’s Health case that was decided by the United States Supreme Court in June of 2016.

Mac is a graduate of Rutgers University and Boston College Law School. He grew up in Chicago and is stilling waiting for the Chicago Cubs to win something, anything. Mac resides in Randolph, MA and is the proud father of two children, Sophie and Atticus, whose random musings will one day serve as the basis either for a very entertaining book or a very foreboding cautionary tale.