Rahm's likely opponents, and some election officials, say Emanuel hasn't done enough to satisfy residency requirements necessary to run for mayor.
Rules stipulate candidates must reside in the city for at least one year before the election.
Last week, Chicago Board of Elections Chairman Langdon Neale said Tuesday that Emanuel is likely to survive any residency challenge, comparing the question to that of a soldier.
"You don't have to live there. It's about intent," he said. Emanuel voted by absentee ballot in February.
But election lawyer Burt Odelson does not agree with Neale. He says Emanuel has a problem getting on the ballot because the law, which dates back to1871 states you must live in your residence for one year, plain and simple.