DENVER -- From the first question, Mitt Romney was on the attack.

So was Barack Obama.

Butduring their 90-minute encounter, the first of three presidentialdebates, the Democratic president sometimes seemed annoyed and defensivewhile his Republican challenger was energetic, focused and relentlesslyon message. Romney ripped Obama's record on the economy with a tonecalculated to convey more sorrow than anger.

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He told the storiesof individuals who have come up to him and his wife, Ann, at campaignevents asking for help in getting a job or saving their home fromforeclosure. "Yes, we can help," he said, looking straight into thecamera, speaking to the millions of voters watching from their homes,not the hundreds in the University of Denver arena. "But it's going totake a different path, not the one we've been on."

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Obamahammered Romney for tax proposals he said didn't add up and economicpolicies he said would benefit the wealthy and damage the middle class.He defended the Affordable Care Act for its most popular provisions,including protecting those with pre-existing medical conditions. But henever raised that secretly recorded video in which Romney described 47%of Americans as "victims" who are dependent on the government and henever pressed Romney on his record as head of Bain Capital - both issueshis campaign has pushed.

When it was over, it was clear whichside was more eager to talk about the debate. Republican surrogatesimmediately flooded the media center. The Democratic ones didn't followuntil several minutes later, and they left while the other side stayedto spin.

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In a serious, rapid-fire discussion, the two men laid outfundamentally different visions for the role of government and the bestway to lead the nation to prosperity.

"Free market and freeenterprise are more effective in bringing down costs than anything,"Romney said in the discussion of health care. "The private market andindividual responsibility always works best."

Obama talked aboutthe responsibilities of citizens to one another and described spendingon education and other programs as an investment that in the end spursgrowth and jobs. "The federal government can't do it all, but it canmake a difference," he said in an exchange in which he extolled AbrahamLincoln.

There wasn't an embarrassing gaffe or a single sharpexchange that defined the evening, as there sometimes is withpresidential debates.

Romneyagain and again reminded voters of their economic woes and blamedObama's policies for contribution to slow job growth, increasingpoverty, home foreclosures. He questioned Obama's economic competence."Going forward with the status quo is not going to cut it for theAmerican people who are struggling today," Romney charged as Obamafrowned.

And Obama again and again raised questions about whetherRomney's numbers added up and if his policies would work, saying his taxproposals would explode the deficit and benefit the wealthy. WhenRomney disputed that, saying he wouldn't reduce the tax burden on thewealthy or approve tax cuts that increased the deficit, the presidentexpressed incredulity.

"Now four weeks before the election, he issaying his big, bold plan is: Never mind," Obama said. He accused Romneyof proposing to "double down" on economic policies that contributed tothe economic meltdown that greeted him four years ago in the OvalOffice.

In other words, Romney cast the election as a referendumon Obama's first term in office. Obama cast it as a choice between hisplans and those of his opponent.

Much of the discussion was afestival for fact-checkers, a dizzying competition of numbers on taxpolicy, on the costs of the proposals each has made, on Romney's recordas governor of Massachusetts and Obama's tenure as president.

Bothmen talked fast, tried to hold the floor and often ignored theentreaties of moderator Jim Lehrer to respond to his specific questionsor to move on to the next topic. At times, they interrupted and talkedover one another.

But Romney showed the value of the 19 debates heparticipated in during the GOP primaries and the extended practicesessions he has scheduled in recent weeks. He seemed relaxed andconversational, repeatedly referred to individuals he had met on thecampaign trail, and gave no quarter when challenged by the president.

Obama,in contrast, hadn't debated since the last of his three encounters withJohn McCain four years ago. Not since then has he faced an opponent on alevel playing field - the podium in front of him not even adorned withthe presidential seal. He understandably didn't seem to relish havinghis record challenged in a direct way presidents rarely face.

After Obama vowed to reduce the federal budget deficit in his second term, Romney told him, "You've been president four years."

BillGalston, an adviser to President Clinton and other Democrats and who isnow at the Brookings Institution, said Romney "did himself considerablegood" in the debate. "I would not be surprised to learn that a majorityof the American people think he won it outright," Galston said in ane-mail. "I suspect that over the next week, the public opinion surveyswill show a significant narrowing of the gap between President Obama andhis re-energized challenger."

"He crushed it," Sen. John Thune, R-S.D., said of Romney. "Most people came away seeing a Mitt Romney they hadn't seen before."

Romney had never participated in a debate in which the audience was so large and the stakes so high.

Sincethe Democratic National Convention last month, polls show Obama hasopened a narrow lead nationwide and a bigger one in such swing states asOhio and New Hampshire. If Obama could be satisfied with a draw, Romneywent into the race needing to shake things up.

The debate offereda more substantive discussion of the two candidates' proposals thanmuch of the campaign to date. Even though the two sides effectively havebeen campaigning against one another for most of the year, the vastmajority of ads have been negative and the points of attack often anill-considered comment by the other guy.

Wednesday night, theyexplored the considerable differences between them on how they wouldspur growth and their views on the role of government in the 21stcentury. The length of the debate, a less rigid format than in previouselections and the focus on four broad topics were designed to encourage asubstantive discussion.

The ideological divide between Obama andRomney on dominant questions of the day - this year, it's the economyand its slow climb out of recession - is as wide as it has been in anypresidential election in more than a generation.

On that, at least, the two contenders seemed to agree.

"Fouryears ago, we were going through a major crisis," Obama said in hisclosing statement. "The question now is: How do we build on thosestrengths?"

Romney, who courtesy of a coin toss got the last word,said a second Obama term would lead to deeper economic travails. Thetwo candidates offer "two very different paths," he said. "They lead invery different directions."