Four Illinois riverboat casinos failed to get the U.S. Supreme Court to hear their challenge to a law requiring them to share their profits with the state's ailing horse racing tracks.

The court's Monday decision means Illinois tracks expect to share in an estimated $80 million -- money set aside under a 2006 law requiring state riverboat casinos that gross over $200 million annually to give 3 percent of their take to the horse racing industry.

The boats -- in Aurora, Elgin, and two in Joliet -- asked the high court to review whether the law violated the U.S. Constitution's prohibition on unwarranted seizure of assets. The Illinois Supreme Court ruled last year that the "takings" clause applies to government acquisition of private land, not taxes.

The casinos had paid the fee in protest and money was set aside in a special state account during the three-year life of the law. About $79 million was in the account at the time of last June's state court ruling.