Former Maryland State Senator, Thomas "Mac" Middleton joined the Cornerstone Annapolis office as a senior consultant in January 2021. Mac possesses nearly four decades of experience working in public service in the state of Maryland. He brings to the firm expertise in economic development, financial services, budget and appropriations, agriculture, energy and environment, and infrastructure policy.

He was elected to the Maryland State Senate in 1994 and initially served on the Senate Budget and Taxation Committee and was Chairman of the Capital Budget Subcommittee. Since 2003, Middleton has served as Chairman of the Finance Committee. As chairman, he led the committee in reviewing all legislation relating to banks and other financial institutions, business regulation and occupations, commercial law, economic development, health, labor, and insurance matters.

Prior to serving in the Senate, Mac was chairman of the Charles County Planning Commission where he worked to better manage growth in the county from 1978 to 1986. In 1986, he was elected President of the Charles County Commissioners and continued to work on improving the county's government services, education, and growth management. Mac has also served as Chairman of the Chesapeake Bay Commission, which is a tri-state legislative body that advises the legislatures of Maryland, Pennsylvania and Virginia, and the U.S. Congress on issues of bay-wide concern and ensures state and federal actions to sustain the living resources of the Chesapeake Bay.

Mac has been the owner and operator of his family farm, Cedar Hill Farm, since 1971 and brings unique insight into challenges faced by small business owners. He is a lifelong Charles County, MD resident, a full-time farmer, husband, father of three, proud grandfather, and strong believer in public service.