Hillary Rodham Clinton joins U.S. Senator Mark Udall, U.S. Senator Michael Bennet, Candidate for Congress Andrew Romanoff and Governor John Hickenlooper in a get out the vote rally at the Radisson Denver Southeast in Aurora... [Getty Images]

AURORA, CO - OCTOBER 21: Hillary Rodham Clinton joins U.S. Senator Mark Udall, U.S. Senator Michael Bennet, Candidate for Congress Andrew Romanoff and Governor John Hickenlooper in a get out the vote rally at the Radisson Denver Southeast in Aurora on Tuesday, Oct. 21, 2014(Kathryn Scott Osler/The Denver Post via Getty Images) — see more

AURORA, CO - OCTOBER 21: Hillary Rodham Clinton joins U.S. Senator Mark Udall, U.S. Senator Michael Bennet, Candidate for Congress Andrew Romanoff and Governor John Hickenlooper in a get out the vote rally at the Radisson Denver Southeast in Aurora on Tuesday, Oct. 21, 2014(Kathryn Scott Osler/The Denver Post via Getty Images)