The state of Michigan, backed by more than a dozen other states, on Monday urged the U.S. Supreme Court to curtail Indian tribes’ immunity from lawsuits over their commercial activities.

At the heart of the dispute between Michigan and the Bay Mills Indian Community, which occupies reservation land within the state, is a small tribal casino that, the state contends, is illegal. But in the background is the lucrative gaming industry in which tribes and an increasing number of states compete for millions of dollars in revenue.