A unanimous court rejected the idea that four Chicago-area riverboat casinos were unconstitutionally targeted by a 2006 law requiring they turn over 3% of their receipts to the racing industry. The casinos, located in Aurora, Elgin, and two in Joliet, complained applying the surcharge only to casinos making more than $200 million a year violated the state constitution’s uniformity clause because it left out five less-lucrative facilities.

A Will County, Ill., judge agreed last year, tossing out the law and sending the challenge directly to the Supreme Court. The casinos, which argue they’re not to blame for racing’s problems, paid the temporary, two-year tax under protest; $79 million sits unused in a state bank account.

The law directs 40% of that go to the state’s five racetracks: Arlington Park, Balmoral Park, Fairmount Park, Hawthorne Race Course, and Maywood Park. The other 60% goes to purses at the tracks. Tens of millions of dollars would go to racing.

A spokesman for the parent company of two of the boats, the Hollywood Casino in Aurora and Empress Casino in Joliet, bemoaned the ruling’s approval for the General Assembly to “cherry-pick a handful of businesses to fund another private industry.”

The court dismissed the boats’ argument that there was no difference between the more lucrative boats and their poorer cousins, and that lawmakers set an unjustified $200-million threshold because the law wouldn’t have won approval with the downstate boats included.

Justice Ann Burke, writing the court’s opinion, noted the downstate boats take in $6 million a month or less, compared to as much as $40 million a month for the Chicago-area casinos.

The casinos could ask the state Supreme Court to reconsider its ruling or even seek a U.S. Supreme Court review because they raised federal constitutional challenges.