U.S. Rep. Cory Gardner celebrates in Denver after he was projected to win the U.S. Senate seat in Colorado on Tuesday, November 4.
Chris Schneider/AP
Colorado's Senate race —
Sen. Mark Udall delivers his concession speech to Democratic supporters in Denver on November 4.
Jack Dempsey/AP
Colorado's Senate race —
Udall exits his campaign bus during an Election Day visit to the University of Colorado in Boulder, Colorado.
Brennan Linsley/AP
Colorado's Senate race —
Gardner joins supporters on the corner of a major intersection in Centennial, Colorado, a Denver suburb, on Election Day.
David Zalubowski/AP
Colorado's Senate race —
Voters in Thornton, Colorado, head into a polling place to drop off their ballots on Election Day.
Jack Dempse/AP
Colorado's Senate race —
Udall makes a point during a debate last month.
David Zalubowsk/AP
Colorado's Senate race —
Gardner was endorsed by The Denver Post newspaper, which backed Udall six years ago.
David Zalubowsk/AP
Colorado's Senate race —
Udall greets supporters at a campaign rally in downtown Denver on October 15. First lady Michelle Obama and former U.S. Secretary of State Hillary Clinton have each pledged their support for Udall and campaigned for him.
David Zalubowski/AP
Colorado's Senate race —
Gardner speaks on Capitol Hill during a hearing on the Affordable Care Act in October 2013. Gardner is a staunch opponent of Obamacare, and he has frequently linked Udall to President Obama's policies.
Alex Wong/Getty Images
Colorado's Senate race —
Udall and Gardner have faced off in several televised debates.