Connecticut's Democrats nominated Spellacy for the United States Senate in 1922, but he was defeated by the incumbent, former governor George P. McLean. He was again a delegate to the 1924 Democratic national convention, supporting Gov. Alfred E. Smith of New York, while himself receiving a vote on each of the 41st and 42nd ballots, and was eastern regional campaign manager for the eventual compromise nominee (chosen after Smith and the other leading contender, William Gibbs McAdoo, deadlocked), John W. Davis.
