Illinois Rep. Debbie Halvorson (D) was planning to get some fundraising help from White House Chief of Staff Rahm Emanuel on Sunday. But the event has been rescheduled amid growing speculation Emanuel is planning to run for mayor of Chicago.

On Tuesday, Chicago Mayor Richard Daley announced he won't run for a seventh term. Speculation about Emanuel's plans has raged since he admitted he wants to return home and run for mayor of Chicago some time in the near future.

"I hope Mayor Daley seeks reelection. I will work and support him if he seeks reelection," the White House chief of staff told PBS's Charlie Rose in an interview in April. "But if Mayor Daley doesn't, one day I would like to run for mayor of the city of Chicago."

White House senior adviser David Axelrod on Wednesday said Emanuel would make a decision soon.

In the meantime, the former congressman hasn't abandoned his commitment to helping Democrats this fall. The event for Halvorson, who is facing a competitive race against Republican Adam Kinzinger, has been rescheduled for Sept. 26, according to NBC Chicago's Ward Room.