 A delegate to the 1844, 1860, 1864 and 1868 Democratic National Conventions, Church, in 1860, advocated the nomination of Stephen A. Douglas.At the Democratic National Convention, held in New York City in July 1868, he was named by the delegation from New York State as its choice for the nomination for the presidency, and his name was presented to the convention by Samuel J. Tilden, the chairman of the delegation, who cast the vote of the State for him for the first seven ballots.New York then switched to Thomas A. Hendricks from the eighth to the twenty-second ballots until a break was made by other states to Horatio Seymour, the chairman of the convention, who was then nominated.