He was a delegate to the Florida State Democratic conventions from 1977 to 1978 and served as member of the Democratic National Finance Council from 1976 to 1978. Stack was elected as a Democrat to the Ninety-sixth Congress (January 3, 1979 – January 3, 1981).
Stack participated in Florida State Democratic conventions from 1977 to 1978 and held a position on the Democratic National Finance Council from 1976 to 1978. He was subsequently elected as a Democrat to serve in the Ninety-sixth Congress (January 3, 1979 – January 3, 1981).