PINE RIDGE, S.D. — Here in the poorest corner of the poorest Indian reservation in the country, Geraldine Blue Bird’s household was one of the worst off. Then President Bill Clinton stopped by her home during his 1999 tour of the nation’s most impoverished places. Ms. Blue Bird, who lived on a disability check, was squeezing 28 adults and children, most of whom she had taken in from the streets, into a four-room shack with no plumbing and a pop-up camper out back. When word got out, donations poured in, and continued for years. Ms. Blue Bird even received a...