He served on the Board of Estimates of Detroit in 1873 and was a member of the Michigan State Senate 1879–1880. He was elected as a Republican to the United States Senate in 1883 after decorated Senator Thomas W. Ferry handpicked Palmer as his successor. He served from March 4, 1883 to March 3, 1889. He was not a candidate for reelection. He was chairman of the Committee on Fisheries in the 49th Congress, and the Committee on Agriculture and Forestry in the 50th Congress. While in the Senate, he became known as an advocate for the women's suffrage movement, immigration restrictions, and homesteader rights. He is credited with coining a phrase widely adopted by latter-day reformers, Equal rights for all, special privileges to none. On February 6, 1885, he delivered a noted speech arguing in favor of an amendment to the U.S. Constitution granting women's suffrage.
