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Sen. Mark Udall's (D-Colo.) late slide continues as a Quinnipiac poll released Thursday finds him now trailing Rep. Cory Gardner by seven points among likely voters, 46 percent to 39 percent. In Quinnipiac's previous survey, Gardner had a five-point lead.

Polls in the closing weeks of the election cycle have shown Gardner pulling away in the race, and FiveThirtyEight now gives him a 75 percent chance of picking off Udall's seat.