Washington (CNN) - With three days to go until the start of the Republican convention, President Barack Obama and GOP challenger Mitt Romney remain deadlocked in the race for the White House, according to a new national survey.
A CNN/ORC International poll released Friday also indicates Romney's favorable rating among those likely to vote in the presidential election is in the same ballpark as the president's, and the survey also points to a slightly higher level of enthusiasm for Republicans than Democrats.
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According to the poll, 49% of likely voters say they're backing Obama, with 47% supporting Romney. The two point margin is within the survey's sampling error, meaning the race is a statistical tie.
Among the larger pool of registered voters, some of whom will stay at home on Election Day, the survey indicates the president holds a 52%-43% lead. That number is little changed from CNN's previous poll, conducted in early August, before Romney named House Budget Chairman Paul Ryan as his running mate.
"Likely voters have traditionally been a more Republican group in past elections because they tend to turn out in higher numbers than Democrats, and 2012 looks like it is no exception. This explains why the margin between President Obama and Mitt Romney is smaller among likely voters," says CNN Polling Director Keating Holland. "But it is a mistake to say that the race has tightened in the past few weeks, given the lack of movement in the results for registered voters."
In an election, it all comes down to turnout, and that's what a likely voter model is all about. The more enthusiastic you are about voting, the likelier you are to actually vote in November. According to the poll, 35% of registered Republicans questioned say they are extremely enthusiastic about voting, six points higher than the 29% of Democrats who feel the same way.
Four years ago, two-thirds of Democrats said they were extremely or very enthusiastic about voting, giving them an 18-point lead over Republicans that helped Obama overcome the fact that turnout has historically been higher among Republicans. Now the two parties are evenly divided.
"Enthusiasm is down among key elements of the Obama coalition from the last presidential election, indicating that some of his supporters are not likely to vote unless something changes. The challenge for the president in his convention is to fire up his base and to turn those potential stay-at-homes into likely voters. If he can do so, the likely voter model may not work as much in Romney's favor in September as it does in August," adds Holland.
In the horserace, 48% of likely voters who are independents say they support Romney, with 45% backing Obama. The gender gap and generational divides seen in polling so far this cycle continue, with the president holding a 54%-42% lead among female likely votes and Romney holding a 53%-43% lead among male likely voters. Obama has a 55%-43% advantage among those under 50, with Romney holding a 50%-45% margin among likely voters 50 and older.
"The two candidates are in a dead heat in the national horserace, tied among likely voters who call themselves independents and tied in the suburbs," says Chief National Correspondent John King.
"Which means the conventions are their best chance to nudge the numbers a bit before we get to what is likely to be a decisive series of debates. The race could break near the end, but heading into the conventions it is as close as can be."
Eighty-seven percent of likely voters say they're minds are made up, with just over one in ten saying they could change their minds on which candidate they'll back in the presidential contest.
The challenge for Romney at his convention, which starts Monday in Tampa, Florida, is to boost his favorable ratings and re-establish the Republican brand nationwide.
According to the poll, 50% of likely voters see Romney in a favorable way, with 46% saying they see him in an unfavorable light. Fifty-two percent say they have a favorable opinion of the president, with 47% saying the see him in an unfavorable way.
While there's not much daylight between the two candidates in this poll when it comes to their favorable/unfavorable ratings, there's more of a disparity between the two political parties in the minds of likely voters.
The poll indicates likely voters are evenly split 47%-47% on how the view the Democratic party. But the GOP has a 43%-51% favorable/unfavorable rating.
As for the running mates, likely voters are divided on Vice President Biden (46%-47%), with a plurality having a favorable opinion of Ryan, the seven-term congressman from Wisconsin (45%-39%).
As for Romney's choice of Ryan as his running mate, 51% of registered voters rate Ryan as an excellent or good pick. And 52% believe he is qualified to be president if necessary.
"From a historical perspective, Ryan ranks in the middle of the pack among recent vice presidential nominees," says Holland. "He's not as well-received as Joe Biden or Dick Cheney initially were, but he's definitely not another Dan Quayle. Joe Lieberman is the running mate who put up numbers most like the ones Ryan now gets."
The survey also indicates the president's approval rating at 50%, unchanged from early August.
According to the poll, two-thirds of likely voters say if elected, Romney will work hard to implement GOP polices on the economy, and six in ten say he would make a real effort to enact Republican proposals on health care. But only 43% feel he will work hard to implement the Republican party's position on abortion.
The social issue has dominated news coverage this week, following controversial comments from Rep. Todd Akin, the Republican Senate nominee in Missouri. The six-term congressman, who has deep ties to Christian conservatives, came under fire following comments in a TV interview Sunday when he said that a woman's body is capable of preventing pregnancy in cases of "legitimate rape" while explaining his stance that there should be no abortion exemption for rape or incest.
The survey indicates that 83% of Americans say that abortion should be legal in cases of rape or incest, with similar numbers believing abortion should be legal when the life or health of the mother is endangered.
"Those aren't topics that Americans like to think about, but the recent controversy over Akin's remarks may have provided a stark reminder to many Americans that there are at least a few circumstances under which they support legal abortion," says Holland.
As a result, the number who believe that abortion should be illegal in all circumstances has dropped from 21% last year to 15% now. Surprisingly, the debate also appears to have boosted the number of Americans who say that abortion should be legal under any circumstances - from 25% a year ago to 35% now, the highest level of support for unrestricted abortion since mid-1990s.
The CNN poll was conducted by ORC International Wednesday and Thursday (August 22-23), with 1,055 adult Americans, including 924 registered voters and 719 likely voters, questioned by telephone. The survey's overall sampling error is plus or minus three percentage points, with a sampling error of plus or minus 3.5% points for likely voters.
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