President Barack Obama arrives to speak at a campaign event at Veteran's Memorial Park in Manchester, New Hampshire, Oct. 18, 2012.
President Barack Obama arrives to speak at a campaign event at Veteran's Memorial Park in Manchester, New Hampshire, Oct. 18, 2012.
Less than three weeks before election day, U.S. public-opinion polls show a very close race for president between the incumbent, President Barack Obama, and his Republican challenger, former Massachusetts governor Mitt Romney.  At the end of the second presidential debate this week, both candidates focused on the themes they want to emphasize in the final days of the campaign.

Mitt Romney continued to hammer away at President Barack Obama's economic record.

"I understand that I can get this country on track again," said Romney.  "We do not have to settle for what we a going through."

The president said his priority was making life better for middle-class Americans.  

"But I also believe that everybody should have a fair shot, and everybody should do their fair share, and everybody should play by the same rules because that is how are economy is grown and that is how we have built the world's greatest middle class," said Obama.

The state of the U.S. economy remains the dominant issue in the campaign, says analyst Alex Roarty of National Journal.

"The governor has gotten very good about laying into the president about the current state of the economy, about promises and things that Obama initially said he would do in office that he has not been able to accomplish," said Roarty.

Analysts said that Romney was especially effective in making his arguments on the economy in the first presidential debate.  His debate performance excited Republicans and gave him a boost in the polls.

But most analysts gave President Obama a slight edge in the second debate.  Obama came off as more forceful and willing to challenge Romney on a wide range of issues.

Noted political reporter and columnist Jules Witcover has covered every presidential election since 1956 and says the president's second debate showing may have slowed the Romney momentum.

"He [Obama] reassured Democrats and maybe others and may not have come all the way back from that first debate, but certainly got back in the ballgame," said Witcover.  "And his demeanor was sharper and at the same time I found that Romney was a bit abrasive."

Roarty, of National Journal, expects President Obama to try to keep the focus on Romney in the closing weeks of the campaign.

"'I can defend what I have done in my first term in office.  I can tell you what I want to do in my second term.  But maybe more than anything else I can tell you why this other guy, Mitt Romney, should not be president,'" said Roarty.

Both candidates used the debates to solidify their base of support and to reach out to the dwindling number of undecided voters, especially in the handful of states where the outcome is in question.

"I think it is a very small number of people, [the number of voters who remain undecided]," explained Tom DeFrank of the New York Daily News.  "The undecided likely voters are probably just maybe a million or so spread over nine states that are really being contested here."

Most of the 50 U.S. states already lean toward one candidate or the other, so the Obama and Romney campaigns will focus on the nine so-called battleground states where the outcome is uncertain in the final days of the campaign.

President Obama will be busy shoring up his base of support among minority and women voters, groups that traditionally prefer Democratic candidates.  Some recent polls show a dip in support for Obama among women, perhaps in response to Romney's performance in the first debate.

Romney hopes to fire up his Republican base to get out and vote, and at the same time appeal to undecided voters and those who supported Obama four years ago, but who are disenchanted with his record on the economy.

The two men meet in one final debate that will deal with foreign policy on Monday in Florida.