Jim Allen of Farmersville quit Thursday at the behest of Reince Priebus, the party's national chairman, and by Rep. Rodney Davis, R-Ill., who faces a primary challenge from the woman Allen attacked, Erika Harold, the Chicago Tribune reported.
Davis described Allen's comments as "incredibly dumb." Stat GOP Chairman Jack Dorgan said they were "offensive and inappropriate."
Harold, a graduate of Harvard Law School and 2003 Miss America, is running against Davis in the March 2014 primary in Illinois' 13th Congressional District. She also sought the nomination in 2012 when Davis was first elected.
In an email to a supporter of Harold, Allen called her the "love child" of the Democratic National Committee and suggested she was backed by Republicans in Name Only or RINO.
In addition to likening her to a "streetwalker," Allen predicted Harold, who formerly worked as a lawyer in Chicago, would end up returning to the city, "working for some law firm that needs to meet their quota for minority hires."
Davis won a narrow victory in 2012 after replacing Rep. Tim Johnson, who decided after the primary not to seek another term. Harold's decision to run has irritated some Republicans in central Illinois who say a primary contest will use up resources needed for another tough general election.