McClatchy-Marist surveys find Republicans leading in Colorado, Pennsylvania and Wisconsin. Details after the jump.
Among likely voters:
— Buck leads incumbent Bennet 50-42% in Colorado
— Toomey nine points ahead of Sestak in Pennsylvania
— Johnson leads Feingold 52-45 in Wisconsin
Conducted Sept. 26-28, error margin 3.5 points
Plus: Chicago Tribune/WGN-TV survey finds Giannoulias 38, Kirk 36 in Illinois Senate.