U.S. 20 slices decisively through rich Iowa farmland, where the dirt is almost as dark as the two-lane asphalt ribbon that bisects the table-flat prairie west of Fort Dodge. The highway dips, then rises gently to Sac City, a town devastated by plunging crop prices, sagging spirits and the near collapse of rural America in the past decade.
In many respects Sac City looks terminal. The population is down to 2,400, from 3,000 in 1980. Fister's Department Store is out of business. Iowa Public Service has trouble collecting electric bills from nearly bankrupt farmers, and the utility's Sac City office has...