Party Polarization (IMAGE) Michigan State University Caption Republicans (red) and Democrats (blue) almost never collaborated in the 2015-2016 U.S. House of Representatives. Credit Zachary Neal Usage Restrictions With credit 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.