The casinos object to a law that forces them to transfer of millions of dollars to ailing horse tracks.

Last year, the state Supreme Court unanimously upheld the law. The high court let that ruling stand Monday without comment.

The renewal of the law in 2008 figures in the case against Blagojevich. FBI wiretaps on telephones in Blagojevich's home and the governor's office showed an alleged effort by the then-governor to shake down a racetrack owner for a sizable campaign contribution while the bill was pending. A lawyer for the owner, John Johnston, has said the contribution was not made.

Four secretly recorded conversations about the issue were played at Blagojevich's impeachment trial in the state Senate.