Seymour served Anaheim as a member of its city council from 1974 to 1978, as the 39th mayor of Anaheim from 1978 to 1982, and as a state senator from 1982 to 1991. In the California Senate, his voting record was that of a moderate or liberal Republican; he voted to ban assault weapons, to outlaw discrimination against people with AIDS, and to increase spending for social programs including education and mental health benefits.[4] As mayor of Anaheim, Seymour was instrumental in recruiting the Los Angeles Rams to move to Anaheim Stadium.[5]
In 1991, Seymour was appointed to the U.S. Senate by GovernorPete Wilson to serve in the seat Wilson had vacated to become governor. Seymour's appointment lasted until the 1992 special election to select a replacement who would serve until the normal expiration of Wilson's term in 1995. Former San Francisco mayorDianne Feinstein defeated Seymour in the special election.
After his Senate term, Seymour served as director of the California Housing Finance Agency for two years,[6] and later served as CEO of the nonprofit Southern California Housing Development Corporation and on the boards of directors of several housing-related companies including IndyMac Bank, Orange Coast Title Insurance, Los Angeles Federal Savings Bank, and Irvine Apartment Communities.[7] Seymour currently lives in San Marcos, California.