[1] Prior to becoming a state legislator, Kelly served one term on the Leicester School Committee and was clerk and treasurer of the Oxford – Rochdale Sewer District.

[2] In 1958, Kelly was elected to the Massachusetts House of Representatives by defeating Republican incumbent John E. Riley 6456 votes to 6045.

Many, including fellow committee member Beryl Cohen, believed that Kelly leaked a damaging report to the Volpe administration, which gave it time to counterattack.

[7] In 1971, Kelly backed Kevin B. Harrington for the Senate Presidency over Ways and Means Committee Chairman James F. Burke.

[10][11][12] Kelly was honored by Massachusetts Fair Share, Public Interest Research Group, and Americans for Democratic Action for his work for the poor, elderly, and disabled.

[7] In recognition of his power as Chairman of Ways and Means and his effectiveness as a member of the Senate leadership, Kelly was widely known as the "Wizard of Oxford".

In 1976, federal prosecutors sought to have Kelly named as an unindicted co-conspirator for his role in the MBM scandal.

The payments allegedly began in January 1971 when Kelly became chairman of the Ways and Means Committee and ended in September 1976.

[19] James L. Bauchat of Masiello and Associates' parent company Kassuba Development Corp., testified that Kelly demanded $10,000 in exchange for state design contracts.

[22] On September 30 he pleaded not guilty and was released by United States magistrate judge Peter W. Princi on $10,000 bond.

[24] Before the retrial, the prosecution attempted to have Tauro removed from the case, citing his pro-defense rulings during the trial and having received assistance from Kelly when Kelly was chair of a committee investigating the Volpe administration and Tauro was Volpe's chief legal counsel.

The United States Court of Appeals ruled that there was no legal basis to bar Tauro from presiding over the retrial.

[31] Kelly then sought to have his sentence delayed until April 1984 so he could complete his studies for a master's degree in business administration at Florida International University.