A new poll has Republican Rep. Cory Gardner ahead in Colorado's tough Senate race.
The independent Quinnipiac University Poll gave Gardner a lead of 48-40 over Democratic Sen Mark Udall. That finding conflicts with two other polls that were released earlier this month that found Udall tied or narrowly ahead.
Colorado's Senate race is one of the most competitive and expensive in the nation. It could help determine who controls the Senate. Republicans need to pick up six seats to take over the chamber.