Washington (CNN) - President Barack Obama's numbers are on the rise in two important indicators of his reelection chances, according to a new national survey.
A CNN/ORC International Poll out Tuesday indicates the president's margins have increased against five possible Republican presidential challengers in hypothetical general election matchups and that Obama's approval rating is up five points since mid-November.
Read full results (pdf).
According to the poll, Obama leads former Massachusetts Gov. Mitt Romney 52%-45% in a possible 2012 showdown. Romney, who's making his second bid for the GOP nomination, held a 51%-47% margin over the president in last month's survey. Obama also holds the same 52%-45% advantage over Rep. Ron Paul of Texas. Last month the president had a 51%-47% margin over Paul, who's making his third run for the White House.
The survey indicates that Newt Gingrich doesn't fare as well against the president in a possible general election matchup, with Obama up by 16 points, 56% to 40%. Last month Obama led Gingrich 53%-45%. The president holds an 18 point advantage over Texas Gov. Rick Perry, up from a seven point margin in November. And he leads Rep. Michele Bachmann of Minnesota by 19 points, up from a 12 point advantage last month.
"Bill Clinton and George W. Bush - the last two presidents who won reelection - had roughly this same amount of support in December of the year before the election, but so did Bush's father in December of 1991. He ended up losing in the general election," says CNN Polling Director Keating Holland. "Polls taken this far in advance of an election are not meant to be predictions of the ultimate outcome."
The survey also indicates that the partisan battle over extending the payroll tax cut may be partially responsible for the jump in the president's approval rating numbers.
According to the poll, 49% of Americans approve of the job Obama's doing in the White House, up five points from last month, with 48% saying they disapprove, down six points from mid-November. The 49% approval rating is the president's highest since May, when his number hit 54% thanks to a bounce following the killing of Osama bin Laden. Since then, in CNN polling, Obama's approval rating has hovered in the mid-40s.
"President Barack Obama's approval rating appears to be fueled by dramatic gains among middle-income Americans," adds Holland. "The data suggest that the debate over the payroll tax is helping Obama's efforts to portray himself as the defender of the middle class."
Obama's gains have come at the expense of the Republicans in Congress and the GOP in general. By a 50% to 31% margin, people questioned say they have more confidence in the president than in congressional Republicans to handle the major issues facing the country. Obama held a much narrower 44% to 39% margin in March.
And the GOP's overall favorable rating has dropped to six points, to 43%, since June, while the Democrats' positive rating remained steady at 55%.
"The Democrats do particularly well among middle income Americans, while the Republicans win support only from the top end of the income scale," adds Holland.
Overall, only 16% say they approve of the job Congress is doing, with 83% giving lawmakers from both parties the thumbs down. The Congressional disapproval rating has topped 80% since August in CNN polling.
The survey indicates that Obama remains personally popular, with three-quarters saying they approve of him as a person.
"Overall, it's not a bad position for an incumbent to be in as the calendar turns to an election year, but there are many months to go," says Holland.
The CNN poll was conducted by ORC International from Dec. 16 to Dec. 18, with 1,015 adult Americans questioned by telephone. The survey's overall sampling error is plus or minus three percentage points.