Please answer the following question: John E. Powers (November 10 1910 July 31 1998) was an American politician who served as President of the Massachusetts Senate from 1959 to 1964.Powers a former clam digger messenger and machine operator served as a State Senator from Boston from 1940 to 1964 and Supreme Judicial Court of Suffolk County from 1964 to 1988. He was twice a candidate for Mayor of Boston. He finished second to incumbent John B. Hynes in the 1955 primary and general election. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Office Holder