Paul Cellucci, the former governor of Massachusetts and ambassador to Canada, died Saturday after a five-year battle with Lou Gehrig’s disease. He was 65. Cellucci served as governor from 1997 to 2001 and was essential in rebranding the state’s Republican Party, focused on conservative principles coupled with a strong environmental agenda and liberal social policies. Although his tax-cutting policies won him praise from conservatives, he also had the respect of liberals after trying—unsuccessfully—to push through one of the toughest assault-weapon bans in the country. Cellucci served four years as the ambassador to Canada under President George W. Bush. Despite his enormous power over Beacon Hill and Washington, he never left his childhood hometown of Hudson and died at his home there.