Twelve jurors and six alternates are to hear opening statements Thursday in Antoin "Tony" Rezko's trial.
U.S. District Judge Amy J. St. Eve says she's not releasing the jurors' names or numbers. She has left the door open to releasing some information later.
The 52-year-old Rezko is accused of shaking down companies hoping to invest teachers' pension money or build hospital expansions. He denies wrongdoing.
Rezko has raised hundreds of thousands of dollars for Blagojevich and sizable amounts for Obama. Neither politician has been charged with anything.