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.
Before becoming a senator, Twilegar was involved in state politics as a member of the Idaho Legislature, where he held positions in both the Idaho House of Representatives (1975-1976) and the Idaho Senate (1977-1982), setting the stage for his later Senate campaign.