 He was elected a member of the Minnesota House of Representatives in 1875, 1876, 1878, and 1881; served in the Minnesota Senate 1882 – 1888; unsuccessful candidate for election as State attorney general in 1882 and as Lieutenant Governor in 1884; retired from law practice in 1884 and engaged in the real estate business; elected as a Republican to the United States House of Representatives in the 51st United States Congress, (March 4, 1889 – March 3, 1891); unsuccessful candidate for reelection in 1890 to the 52nd Congress; delegate to the Republican National Convention in 1892;

After resuming his real estate business in Moorhead, Comstock also engaged in manufacturing farm implements in 1893.He was a member of the State normal school board from 1897 to 1905, and retired from business pursuits and resided in Moorhead, Minnesota, until his death there June 3, 1933.He was buried at Prairie Home Cemetery.