Thayer was a member of the New York State Assembly (Franklin Co.) in 1916, 1917, 1918, 1919 and 1920; and was Chairman of the Committee on Public Printing in 1918.
On March 29, 1934, Thayer was accused before the Federal Trade Commission of having received money from the Associated Gas and Electric Company of Albany, to act as a lobbyist for the company while being chairman of the senate committee in charge of the pertaining legislation.
Thayer resigned his seat on June 11, while the Legislature was in recess.
The State Senate met on June 19 for a special session, and found Thayer guilty of official misconduct (and would have removed Thayer from office, had he not resigned) by the unanimous vote of the 47 senators present.
Thayer died on March 9, 1956, in Alice Hyde Hospital in Malone, New York; and was buried at the East Side Cemetery in Chateaugay, New York.