In 1988, after considerable lobbying effort by Indian tribes, the gaming industry and easy-money interests, Congress passed the Indian Gaming Regulatory Act (IGRA).

According to Wikipedia, the purpose of IGRA “is to provide a statutory basis for the operation of gaming by tribes to promote tribal economic development, self-sufficiency and strong tribal governments”.

Of the 556 federally recognized tribes in the U.S., 220-plus tribes in 29 states own/operate 350 gaming enterprises that generate over $26.5 billion in revenues annually, or roughly $120-plus million per year on average per tribe....