The son of a police officer and small business owner, Sean attended Guilford public schools and worked his way through high school and Boston College. After graduating, Sean returned to Connecticut with the goal of helping others. He began working as an aide for U.S. Senator Chris Murphy where he helped the Senator fight for gun safety and better health care, as well as addressing constituent concerns. In Guilford, he worked with neighbors to organize successful grassroots campaigns to build a new high school and institute a full-day kindergarten. In 2014, Sean was elected State Representative for Connecticut’s 98th District. In the House, Sean became a champion for health care reform, a passion rooted in his own life experiences coming from a family that was often uninsured or underinsured. As chairman of the legislature's Insurance Committee, Sean wrote and passed legislation protecting people with pre-existing conditions from insurance discrimination, established the lowest monthly co-pay cap for insulin in the nation at $25, prevented insurance companies from covering mental health differently than physical health, required health insurance plans to cover ten "Essential Health Benefits," and created Connecticut's first prescription drug price transparency law.