McLean got his start in politics as a member of the Beverly Board of Aldermen.
After six consecutive two-year terms, McLean chose not to run for reelection.
[6] In 1960 he played a key role in John A. Volpe's successful effort to win the party's endorsement at the state Republican Convention.
Volpe later won the Republican nomination and defeated Democrat Joseph D. Ward in the general election.
[1] In 1961, Volpe appointed McLean to serve as Chairman of the State Appellate Tax Board, a position he held until his retirement in March 1980.