Pablo Martinez Monsivais / AP President Barack Obama walks during his visit to the Hoover Dam, Tuesday, Oct. 2, 2012 in Boulder City, Nev.

On the eve of the first presidential debate, President Barack Obama maintains his national lead over Mitt Romney, but the Republican nominee is well within striking distance, according to the latest NBC News/Wall Street Journal poll.

Obama edges Romney by three points among likely voters, 49 percent to 46 percent, which is within the survey’s margin of error. Obama’s lead was five points, 50 percent to 45 percent, in the NBC/WSJ poll released two weeks ago, following the political conventions.

But among a wider pool of registered voters, the president is ahead of Romney by seven points, 51 percent to 44 percent.

Democratic pollster Peter D. Hart, who conducted this survey with Republican pollster Bill McInturff, argues that the poll results contain good news for both candidates.

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For Obama, he’s ahead at a time of growing optimism about the economy and nation’s direction. For Romney, it’s a “margin of error” contest that comes as interest in the upcoming election lags among key Democratic constituencies versus four years ago.

But Hart adds, “Barack Obama has the better hand.”

Read the entire poll here (.pdf)

Indeed, the poll also shows the toll the past month has taken on Romney, with a majority of registered voters saying that the events of the last couple of weeks had given them a less favorable impression of the Republican challenger.

What’s more, by a 2-to-1 margin, these voters have a negative reaction to Romney’s comment – caught on tape from a fundraiser back in May – that “47 percent” of Americans are dependent on government and believe they are victims.

Why the race is closer among likely voters

Among the full universe of registered voters in the poll, Obama leads Romney with African Americans (95 percent to 3 percent), Latinos (winning seven in 10), women (56 percent to 40 percent), and independents (48 percent to 35 percent).

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Romney, meanwhile, has the advantage with whites (54 percent to 41 percent), seniors (52 percent to 43 percent), suburban residents (51 percent to 45 percent), and men (48 percent to 45 percent).

But among voters expressing the highest interest in the election, Obama and Romney are essentially tied (49 percent to 48 percent).

And two key pillars of Obama’s political coalition – Latinos and young voters – are much less interested in the election than they were in 2008.

“That helps to explain why it’s close among likely voters,” Hart says.

Likely voters are defined in the survey as those expressing the highest interest in the upcoming presidential contest (either a “9” or “10” on a 10-point scale), and those who have participated in recent or past elections.

Economic optimism rising

While the race is closer among likely voters, the poll has this good news for Obama: optimism about the economy continues to increase.

Forty-four percent believe that the economy will improve in the next 12 months. That’s up from two points in the last NBC/WSJ survey, eight points since August and a whopping 17 points since July.

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What’s more, 57 percent think that the U.S. economy is recovering, versus 39 percent who disagree with that notion.

And four in 10 now say the country is headed in the right direction, which is the highest percentage on this question since June 2009.

“We have a different feeling about the economy than we did this summer,” says McInturff, the Republican pollster.

McInturff explains that much of this increased economic optimism is coming from Democrats, whose attitudes are matching their ballot preference. But he adds that it’s also coming from political independents and even some Republicans.

Obama vs. Romney on the issues

Given the increased economic optimism, Obama and Romney are nearly tied on which candidate would better handle the economy, with 45 percent picking Romney and 42 percent choosing Obama.

Read the entire poll here (.pdf)

But Obama leads Romney on almost all other issues and character traits – looking out for the middle class (53 percent to 34 percent), handing the situation in the Middle East (48 percent to 32 percent), handling immigration (45 percent to 31 percent), dealing with Medicare (48 percent to 36 percent), being a good commander in chief (47 percent to 39 percent), handling foreign policy (46 percent to 40 percent), and dealing with taxes (46 percent to 41 percent).

Romney, meanwhile, holds the edge on dealing with the federal budget deficit (43 percent to 34 percent) and dealing with the economic challenges that the U.S. faces from China (45 percent to 37 percent).

And the two are tied on who is better equipped to change “business as usual” in Washington (36 percent to 36 percent).

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While Obama enjoys an advantage over Romney when it comes to foreign policy, just 45 percent approve of the way he has handled the recent unrest in Egypt, Libya, and other Arab countries.

The president’s overall job-approval rating stands at 49 percent, while 46 approve of his handling of the economy.

‘47 percent’ takes a toll on Romney

The poll – which was conducted Sept. 26-30 – comes after intense scrutiny and TV-ad attacks on Romney’s “47 percent” comment, in which he said that percentage of Americans don’t pay income taxes, are dependent on government, and believe that they are victims.

After hearing a full description of that comment, 45 percent of registered voters said it gave them a more negative impression of the GOP presidential nominee, versus 23 percent who had a more positive view.

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By contrast, when the same respondents were read a full description of Obama’s “You didn’t build that” line – comments Republicans seized on to portray the president as anti-business – 36 percent had a positive reaction and 32 percent had a negative reaction.

In addition, 51 percent say that what they've heard, seen, and read about Romney in the past couple of weeks gives them a less favorable impression of the former Massachusetts governor, compared with just 36 percent who say the same of Obama.

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Overall in the survey, 44 percent say they have a negative view of Romney, while 41 have a positive view.

That 41-44 favorable/unfavorable rating is lower than Obama’s own 52-42 rating. And it’s lower than every other presidential nominee’s score at this similar point of time in the history of the poll – except for George H.W. Bush’s 34-52 rating in October 1992.

Will the debates change things?

Looking ahead to the presidential debates, nearly four-in-10 registered voters say that the upcoming debates will be either "extremely" or "quite" important in helping determine their vote in the presidential race.

Still, more than 60 percent say that the debates are either "just somewhat important" or "not at all important" to their votes.

McInturff, the GOP pollster, doubts that the debates will change the fundamentals of this contest.

“It would take an episode of some magnitude to disrupt the structural lock in these numbers,” he says.

The NBC/WSJ poll was conducted Sept. 26-30 of 1,000 registered voters (including 300 cell phone-only respondents), and it has a margin of error of plus-minus 3.1 percentage points. The margin of error for the 832 likely voters is plus-minus 3.4 percentage points.