What Obama didn't say
During their 90-minute debate last night, US president Barack Obama spoke for four minutes longer than Republican challenger Mitt Romney.
But when the debate was over, it was what Mr Obama didn't say that defined the evening - and helped make it a good one for Mr Romney.
In a debate that largely was a mix of campaign talking points and tedious policy detail, the themes that Mr Obama's campaign have emphasized to drive down Mr Romney's approval ratings did not surface.
Mr Obama did not mention Mr Romney's work at Bain Capital, the private equity firm whose role in sending thousands of jobs overseas has been cited by Mr Obama's campaign as it has portrayed Mr Romney as a job-killer.
Mr Obama resisted chiding Mr Romney about the former Massachusetts governor's reluctance to release more than two years of his income taxes. Democrats have questioned whether Mr Romney - who has a fortune estimated at up to $250 million - is hiding something about his finances and why he keeps millions of dollars in offshore accounts.
But Mr Obama's most startling omission was not uttering a phrase that has dominated the campaign for much of the past two weeks: "47 per cent."
That would be the percentage of Americans who Mr Romney - speaking at a private fundraiser that was secretly videotaped in May - said were "victims" who are dependent upon government benefits and are unlikely to vote for him.
The video of Mr Romney's remarks, which surfaced last month, was a benchmark in the campaign. Last week, Mr Obama's team released an ad featuring Mr Romney's "47 per cent" comment in seven key states, including Colorado, the host of last night's debate.
Many voters say that Mitt Romney's comments had given them a negative opinion of the former Massachusetts governor.
Nearly six in 10 people said in a Reuters/Ipsos poll released last month that they felt Romney unfairly dismissed almost half of Americans as victims.
In the fallout from the video, Mr Obama's small lead over Mr Romney in nationwide polls increased by a few points. Meanwhile, Republicans campaigning in tight US House and Senate races across the country tried to distance themselves from Mr Romney's remarks.
So it was widely expected that Mr Obama would remind voters of Mr Romney's video during the debate, which was projected to draw a national television audience of about 60 million viewers.
Moderator Jim Lehrer appeared to invite Mr Obama to do just that during one of the debate's final segments. "Do you believe there's a fundamental difference between the two of you as to how you view the mission of the federal government?" Mr Lehrer asked.
"The federal government has the capacity to help open up opportunity and create ladders of opportunity and to create frameworks where the American people can succeed," Mr Obama said.
Obama campaign advisers defended the president's response. "The president wasn't looking at a checklist of attack lines. He was trying to explain his plans," said campaign spokesman Jen Psaki.
Romney supporters said that Mr Obama's avoidance of the topics that could have put their candidate on theb defence might signal a shift in strategy by the president's team.
"It could be that the Obama folks don't feel it's a good vehicle for them anymore," said Romney senior adviser Kevin Madden.
Mr Obama also mostly held his tongue when it came to an accomplishment that vice president Joe Biden has said should be among the top reasons to re-elect Mr Obama: the successful mission by US forces that killed Osama bin Laden.
In a debate that focused on domestic policy, Mr Obama made no mention of the mastermind of the September 11th, 2001, attacks until the closing minutes of the debate.
In wrapping up the debate, Mr Obama again avoided the anti-Romney themes that have been hallmarks of his campaign.
Instead, Mr Obama acknowledged there were areas in which he had fallen short as president.
"You know, four years ago, I said that I'm not a perfect man and I wouldn't be a perfect president," Mr Obama said. "And that's probably a promise that Governor Romney thinks I've kept."