Romney sought to burnish his credentials as a potential commander in chief with a foreign policy address before Virginia Military Institute cadets, asserting that Obama's efforts have been weak in the volatile Middle East and his leadership in world affairs lacking overall.
Obama's aides said the president was upbeat in private, well aware that he had to do better in next week's debate in New York, but steady and looking forward to another shot.
Based on the presumed outcome of the 41 non-battleground states and Washington, D.C., Obama enters the final period banking on 237 electoral votes. Romney is assured of 191.
On the road to 270, the battleground states account for the final 110 electoral votes: Ohio, Florida, Iowa, Nevada, Wisconsin, New Hampshire, Virginia, North Carolina and Colorado.
Both Democrats and Republicans say internal campaign surveys following last week's debate show Romney cut into the lead Obama had built up in many key battleground states. But they say Obama still has an advantage in most of them.
A lack of independent polling makes it difficult to know whether that's true. Romney pulled ahead of Obama, 49 to 45 percent nationally, among likely voters in a Pew Research Center poll conducted after the debate.
TV-watching voters in the contested states continued to get inundated with negative ads from both sides.
"He doesn't have anything to run on so he's running all of these ads, outspending us here in Ohio trying to basically call us liars," Republican vice presidential nominee Paul Ryan told WTOL, a TV station in Toledo, Ohio.
Ryan and Vice President Joe Biden debate Thursday in Kentucky.