Horton was a delegate to the Republican National Conventions in 1928 and 1936, and was a Republican National committeeman from 1937 to 1948. He was elected as a Republican to the Seventy-sixth Congress, serving from January 3, 1939, to January 3, 1941. He was an unsuccessful candidate for reelection in 1940 to the Seventy-seventh Congress, and resumed his former pursuits in Saddlestring as the Owner and operator of the HF Bar Ranch. He died in Sheridan, Wyoming; interment was in Willowgrove Cemetery, Buffalo, Wyoming.