By the time of New York's 1839 election for U.S. Senator, Tallmadge had become identified with the Whigs, who nominated him for reelection. Democrats controlled the State Senate, and they objected to Tallmadge because of his decision to abandon Van Buren. By refusing to vote, the Democrats in the State Senate prevented any candidate from obtaining a majority. As a result of the legislature's failure to make a choice, Tallmadge's seat became vacant on March 4, 1839. By 1840, the Whigs controlled both houses of the legislature. On January 13, 1840, they reelected Tallmadge to the Senate, and indicated in their approved resolutions that the effective date was as of March 4, 1839. He took his seat on January 27, 1840, and served until June 17, 1844, when he resigned to accept appointment as a territorial governor.