Prior to his Senate run Twilegar was a member of the Idaho Legislature, serving in the Idaho House of Representatives from 1975 to 1976 and the Idaho Senate from 1977 to 1982.
Twilegar's political career began with his tenure in the Idaho Legislature, which included stints in both the Idaho House of Representatives (1975-1976) and the Idaho Senate (1977-1982), before he ran for the U.S. Senate.