Matt Grossmann, Michigan State University (IMAGE) Michigan State University Caption Matt Grossmann, assistant professor of political science at Michigan State University, argues that special interest groups are not responsible for the partisan divide in Congress. Credit Michigan State University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.