[3] Later that year, MacLean challenged incumbent state senator Robert M. Hunt for the seat in the Bristol and Plymouth district.

[5] He also gained a reputation for working on behalf of a number of special interest groups, including beer distributors, the real estate industry, and racetracks.

[6][7] In 1989, The Boston Globe, reported that after MacLean played a pivotal role in the passage of a bill that allowed PEBSCO Nationwide Retirements Investments to sell its services to local governments in Massachusetts.

In 1990, federal prosecutors convened a grand jury to look into MacLean's dealings with PEBSCO, but due to a lack of witnesses, the case was dropped in 1991.

According to prosecutors, MacLean received half the fees former Attorney General Edward J. McCormack Jr. made from developing, constructing, and managing Fairhaven Village, a housing development for elderly and low-income residents that received state funding, through Sky High Realty Trust, a trust whose sole beneficiary was MacLean's wife, Marjorie.

McLean was also accused of receiving a portion of the money ($278,090) PEBSCO earned by selling its plan to state employees through hidden payments made through Pilgrim Insurance Agency, which was also owned by McCormack.