The two men vying to represent the 6th Congressional District traded insults Monday night during a debate. Incumbent U.S. Rep. Peter Roskam, R-Wheaton, sparred with Democrat Sean Casten, D-Downers Grove, during a live forum hosted by WTTW. The highly competitive race has sparked national interest, as Roskam holds one of the 23 seats Democrats hope to flip in November with a so-called blue wave and retake the U.S.