In the fifty years between 1940 and 1990, the Rust Belt states lost political clout, while the Sunbelt states gained it — measured here in congressional seats (which are apportioned based on population). Sunbelt states gained 66 seats, with the Rust Belt losing 44. This shifting political geography helped undermine the liberal coalition, which was strongest in industrial states with large labor unions, and paved the way for the rise of the conservative coalition, which was strongest in southern and Bible Belt states, as well as California. Source: Office of the Clerk of the House, clerk.house.gov/art_history/house_history/congApp/bystate.html.