From Moline to Macon County, and back up to DuPage, the ballots didn't fit.
After the polls closed Tuesday night in Aurora they went through the ballots by hand. The problem: The way the ballot forms were cut.
Although the presidential race was called early, in close local contests the misshapen ballots might delay full results until Wednesday.
Two election contractors provided the problem ballots. Both used the same printer in west suburban Addison.
In a news release, ABS Graphics says it has identified a single production line in which the trim was a bit wider than could fit in the machines. It says testing did not reveal the problems.
The company says only a fraction of the ballots were affected, but the Illinois State Board of Elections says the problem ballots turned up in nearly a quarter of the state's 102 counties. The problem affected hundreds, if not thousands of ballots.
"We're talking about a relatively small handful of ballots," said Dan Curry, election commission spokesman for DuPage County. "It's not a huge problem."Even in affected counties, many precincts reported that all their ballots were the proper size. In DuPage County, for instance, Curry said fewer than 25 precincts out of more than 350 came across faulty ballots.
"In Cook County, both Chicago and suburban Cook have a different equipment than most of these counties. We have a blended system," said Cook County Clerk David Orr. "Voters have a choice between touch screen and paper ballots. In most of these counties they have a different vendor and they have primarily what they call optical scan ballots--paper ballots that are fed into a scanner."
"It was pretty smooth sailing today. The only downer is that our voters didn't come out to take advantage of a rather smooth election with great weather, but no voter engagement," said Chicago Election Chairman Langdon Neal.
Chicago election officials say this may be the lowest turnout for a presidential primary in modern history. Board of Election spokesman Jim Allen says turnout was expected to be around 24 percent. That would be lower than any time since at least World War II.
The Associated Press contributed to this report.