CHICAGO (WLS) -- The petitions are all filed in the race for mayor, so now the behind-the-scenes trench warfare begins. With 21 candidates unofficially in the running, many will be trying to keep others from getting on the actual ballot.
The petition challenging process is tedious work, but if a candidate can show that one of his or her rivals collected enough signatures that aren't valid, it can keep that person from getting on the ballot.
The dirty work of the campaign season is well underway at the Chicago Board of Elections. This is where campaigns send their teams to review those stacks of petitions filed by the candidates for mayor, alderman and other city offices, to make sure all the signatures are valid.
"They're trying to determine whether or not there's a registered voter at that address, whether they're in the proper ward if it's for an aldermanic office, whether their signature's authentic or whether they're registered at all," said Jim Allen, from the Chicago Board of Elections.
Burt Odelson, a long-time election attorney famous for challenging Mayor Rahm Emanuel's residency eight years ago and now working for mayoral candidate Paul Vallas, said campaigns also take a look at who circulated the petitions. Sometimes those people are volunteers, other times they are paid per signature.
"We look at the circulators themselves to see if there are 'super circulators,' the super circulators meaning someone who has circulated 100 or more sheets, with 15 names on a sheet in a short amount of time," Odelson said. That could be an indication that the signatures are faked.
On Tuesday, ABC7 Eyewitness News noticed someone was checking Susana Mendoza's signatures. She was confident about them Monday, but is potentially vulnerable because she only filed twice the required number of signatures. Odelson said most election lawyers estimate that 50 percent of signatures a candidate collects are not voters registered in Chicago. Therefore, the more signatures a candidate can collect, the better.
Because candidates are competing for votes and money, they often challenge those who would mostly likely draw from the same pool.
"I would imagine that 10-12 will get challenged and maybe a few more. I would anticipate there will be 10 or 12 left at the end," Odelson said.
Challenges have to be filed by Dec. 3. At the request of several candidates, the Board of Elections will be staying open late and on weekends to accommodate the petition review process. After that, hearing officers will review the challenges and hear from lawyers, and that process could drag on into early January.
Chicago mayoral election: final field could be halved after petition challenges, expert says