On April 30, 1807, he defeated the incumbent Governor Morgan Lewis – Tompkins received 35,074 votes, Lewis 30,989 – and remained in office as Governor of New York until 1817. He was reelected in 1810, defeating Jonas Platt – Tompkins 43,094 votes, Jonas Platt 36,484. In 1813 he defeated Stephen Van Rensselaer – Tompkins 43,324 votes, Van Rensselaer 39,718 – and in 1816, he beat Rufus King – Tompkins 45,412 votes, King 38,647. Tompkins was supported by Dewitt Clinton in his first run for office, but Tompkins later broke with Clinton by supporting James Madison over Clinton in the 1808 presidential election.