In his first campaign for public office in 1958, Bellotti was the Democratic nominee for district attorney of Norfolk County, Massachusetts, but was defeated in the general election.[5] In 1962 Bellotti was elected lieutenant governor and served a two-year term.
In 1964, he challenged the sitting governor of his own party, Endicott Peabody, and defeated Peabody in the Democratic primary. However, he went on to lose the general election to John A. Volpe, with Volpe regaining the seat that he had lost two years earlier. In 1966, Bellotti was the Democratic nominee for Massachusetts Attorney General, but was defeated by Republican Elliot Richardson.[6]
In 1974 he was elected to the attorney-generalship for what was now a four-year term and was reelected twice (serving until 1987).[7]
Bellotti turned 100 on May 3, 2023, and died at his home in Hingham, Massachusetts December 17, 2024, at the age of 101.[11][12][13][14]
Reflecting on Bellotti's legacy following his death, the current Massachusetts Attorney General Andrea Campbell wrote in The Boston Globe that: "His forward thinking and innovation positioned the attorney general’s office as a guardian of the rule of law and social justice. He wielded the law to protect fundamental rights and uphold public trust. He put fairness above all else."[15]