Chicago's mayor has one less challenger. Incumbent Rahm Emanuel wishes Karen Lewis a quick recovery from her cancerous brain tumor.
The Chicago Teachers Union president says she won't run for the mayor's office.
Lewis was seen as Emanuel's most credible re-election opponent. She often tussled with the mayor during the 2012 public schools teachers' strike.
In a statement, Emanuel said he respected and admired Lewis' willingness to be part of the conversation about Chicago's future. He said he looks forward to seeing her back on her feet.
Chicago Alderman Bob Fioretti announced his mayoral bid last month. He said he knows Lewis is resilient and "will be back advocating for educators, students and Chicagoans in no time.''