Mario is a partner at EducationCounsel, a mission-based practice within the Nelson Mullins law firm that combines experience in policy, strategy, law, and advocacy to drive significant improvements in the U.S. education system to help all children thrive. Mario also serves as a Professor of Practice with the Children's Equity Project at Arizona State University, a senior advisor to the Stanford Center for Early Childhood, and a board member to the Alliance for Early Success.

Previously, Mario held senior staff positions in the White House Domestic Policy Council during the Biden and Obama Administrations. He was also a principal advisor for early childhood education to the Chair of the Senate Health, Education, Labor & Pensions Committee. Mario also served as Chief of Policy, Practice, and Research for Child Care Aware of America, the nation’s leading voice for child care. He began his legal career at a national law firm, where he focused on complex commercial litigation and maintained a robust pro bono practice dedicated to advancing civil rights.