KCNC-CBS4 will broadcast debates by the candidates in three closely-contested Colorado congressional races Oct. 17-19. The three taped debates will air at 6:30 p.m. The schedule: -- House District 4: U.S. Rep. Cory Gardner, the Republican incumbent, versus Democratic challenger Brandon Shaffer, on Wednesday, Oct. 17. Debate topics include the farm bill, the energy industry and the economy. -- House District 6: U.S.