A new Pew Research Center poll shows Mitt Romney leading by four percentage points, 49 to 45 percent, over President Barack Obama among likely voters. The previous Pew poll, conducted last month, showed Obama with an eight percentage point advantage (51 to 43 percent). The polls demographic variables show that Romney's 12 percentage point swing in the polls was due, in part, to shifting allegiances among women and young voters.
Romney gained among almost every demographic group, based upon registered voters. His strongest gains were among those aged 30 to 49, 18- to 29-year-olds, those with some college education, whites and women.
Among 30- to 49-year-olds, there was a 21 percentage point swing. In September, 57 percent supported Obama and 47 percent supported Romney. In the new poll, 45 percent support Obama and 56 percent support Romney.
Among 18- to 29-year-olds, there was a 17 percentage point swing. In September, 65 percent supported Obama and 32 percent supported Romney. In the new poll, 58 percent support Obama and 42 percent support Romney.
Among those with some college education, there was a 19 percentage point swing. In September, 53 percent supported Obama and 44 percent supported Romney. In the new poll, 45 percent support Obama and 55 percent support Romney.
Among whites, there was a 15 percentage point swing. In September, 48 percent supported Obama and 51 percent supported Romney. In the new poll, 41 percent support Obama and 59 percent support Romney.
Among women, there was a 15 percentage point swing. In September, 60 percent supported Obama and 42 percent supported Romney. In the new poll, 51 percent support Obama and 48 percent support Romney.
There was only one demographic group where Obama showed a small gain. Among 50- to 64-year-olds, Obama gained three percentage points on Romney and now holds a 55 to 42 percent advantage. (Pew did not include results for Latinos.)
Pew asked respondents which candidate would do better on a series of issues. The poll shows Romney gaining ground on all those issues.
Romney's advantage on reducing the federal deficit grew from three to 15 percentage points. On improving the job situation the advantage shifted from Obama having a one percentage point advantage to Romney having an eight percentage point advantage. On dealing with taxes, Obama lost his six point advantage and Romney now has a four percentage point advantage.
On dealing with Medicare and health care, Obama has a three percentage point advantage, but in September that advantage was 13 percentage points. And on making wise foreign policy decisions, Obama has gone from a 15 percentage point advantage to a four percentage point advantage.
The Pew poll comes after what was widely viewed as a strong debate performance for Romney and weak debate performance for Obama last Wednesday. When asked who did better in the debate, 66 percent chose Romney, 20 percent chose Obama and 13 percent said neither, both or they do not know.
The Obama campaign has been targeting women voters. In ads and speeches the campaign accuses Romney of waging a "war on women" and criticizes him for wanting to cut federal funding to Planned Parenthood, the nation's largest abortion provider.
Young voters are also a key demographic group for Obama. In 2008, 66 percent favored Obama.
The Oct. 4-7 poll had 1,511 respondents, including 1,201 registered voters and 1,112 likely voters. The margin of error is plus or minus 3.3 percentage points for registered voters and 3.4 percentage points for likely voters.