Illinois House Speaker and state Democratic Party chairman Michael Madigan is dumping a longtime political aide after allegations of sexual harassment. Madigan is firing aide Kevin Quinn, younger brother of Alderman Marty Quinn, from several posts in Madigan’s political organizations and in the speaker’s office where he’s worked for nearly 20 years. The move comes after Madigan’s office investigated November complaints from a female worker who said Quinn sent her inappropriate text messages and made unwanted adavances. Quinn hasn’t commented. Madigan says the investigation is also prompting changes in his organization to prevent bad behavior and to react quickly if it occurs.