David Green is the third Democrat to jump in the 13th congressional district race. Green is a social policy analyst at the University of Illinois' Center for Prevention Research and Development. He plans to run an "insurgent campaign" and wants to "appeal to leftists in the Democratic Party, those who identify with other leftist parties, including the Green Party and anti-war libertarians." To learn more about Green, check out his interview in The News-Gazette.

The two other Democrats running in the 13th congressional district include retired Edwardsville judge Ann Callis and U of I physicist George Gollin. 

The incumbent, Republican Rodney Davis, is up against former Miss America Erika Harold in the district's GOP primary.