Illinois state prosecutors have now opened a formal investigation into thousands of robo-calls that disrupted polling places across Chicago.

2,000 judges failed to show up to polling place Tuesday because they were misled to think they couldn’t work. It led to long lines at polling places.

“Somebody called with the intent to create confusion,” Mayor Rahm Emanuel said Wednesday.. “Who did it? How did they get the list? Who paid for it? We have to get to the bottom of it.”

Emanuel is among those calling for a federal robo-call investigation. They are incensed that democracy could be made so difficult for so many.

“As far as we can tell, somebody got a list with names and numbers and called them,” Emanuel said. “Not to educate them. Not to promote the democratic process. But to sow confusion.”

The office of State’s Attorney Anita Alvarez will only confirm an investigation is underway into those calls and who made them, but that’s just one of the complaints brought to law enforcement in the course of an extraordinarily long and frustrating election night.

Other delays on Election Day were caused by same-day registration and short-staffing. The Board of Elections says it’s learning from the challenges.

Workers spent today manually opening and sorting about 15,000 mail-in and provisional ballots. They hope to get through the same number tomorrow.