Sean Casten will take the Illinois Congressional District 6 seat after beating out incumbent Peter Roskam in Tuesday's election. Roskam, R-Wheaton faced Casten, D-Downers Grove, in the midterm race. The district stretches from Crystal Lake to Darien and covers portions of DuPage, Lake, Kane, McHenry and Cook counties. Roskam served in the office for six terms, since 2006.