And, as Obama deputy campaign manager Stephanie Cutter says, "it really now comes down to that small segment of undecided voters."
She told NBC's "Today" show, "The ground game is incredibly important at this point." But she added, "We feel pretty good about where we are." Tonight's debate will focus on foreign policy -- and the issue of Iran's nuclear program is certain to be addressed.
Romney campaign foreign policy adviser Dan Senor told NBC today that Romney's approach to Iran is that "we've got to reach a diplomatic solution."
He said the Obama administration's policy on Iran for the past four years hasn't discouraged Tehran from moving forward with its nuclear ambitions.
Republicans over the weekend accused Obama of leaking word of possible negotiations with Iran for political gain. Throughout the campaign, foreign policy has been an Obama strength -- but some recent polls show his advantage narrowing.
A Pew Research Center poll last month found that 47 percent of those surveyed favored Obama to make "wise decisions about foreign policy," while 43 percent preferred Romney.
(Copyright 2012 by The Associated Press. All Rights Reserved.)