50% of the US economic strength is in the orange section. 50% is in the blue. To quote a civil engineer I am friends with (who really needs to come to the better service):
"national economies are just grab-bags of city economies...and rural areas depend on urban productivity to survive. When cities get weak and stagnant, the entire country slides into deeper poverty--rural areas, by contrast, are stagnant by default, except when made prosperous by economic forces from cities: demand for resources, labor, etc."