THORNTON, CO - OCTOBER 25: U.S. Senator Mark Udall, background, was joined by fellow U.S. Senator Michael Bennet, right, at a canvass kickoff campaign on October 25, 2014 in Thornton, Colorado. Udall is seeking reelection as one of Colorado's two senators and faces Republican challenger Cory Gardner in a tight race for the seat. (Photo by Marc Piscotty/Getty Images)
