Kennedy was "always ready to help less fortunate fellow Irishmen with a little cash and some sensible advice." He enjoyed the approval and respect of most folks in East Boston, living on the hill of a mixed Boston neighborhood of upscale Irish and Protestant elite. Beginning in 1884, he converted his popularity into five consecutive one-year terms in the Massachusetts House of Representatives, followed by three two-year terms in the Massachusetts Senate. Establishing himself as one of Boston's principal Democratic leaders, he was invited to give one of the seconding speeches for Grover Cleveland at the party's 1888 national convention in St. Louis. However, he found campaigning, speech making, and legislative maneuvering, to be less appealing than the behind-the-scenes machinations that characterized so much of Boston politics in the late-nineteenth and early-twentieth centuries. After leaving the Senate in 1895, Kennedy spent his political career as an appointed elections commissioner, an appointed fire commissioner, as the backroom boss of Boston's Ward Two, and as a member of his party's unofficial Board of Strategy.