PRINCETON, NJ -- Barack Obama has a 48% to 39% advantage over Mitt Romney among independent voters in 12 key swing states. He first moved ahead of Romney among this group in February after being tied in January and trailing last year.
The results are based on the most recent USA Today/Gallup Swing States poll, conducted March 20-26, among voters in Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, Virginia, and Wisconsin.
The poll preceded Romney's Tuesday victory in the key Wisconsin primary that made his nomination look increasingly inevitable. Romney's closest pursuer in the Republican nomination race, Rick Santorum, fared much worse versus Obama among independents in the Swing State poll, trailing 53% to 32%.
Overall, Obama leads Romney by 51% to 42% in the swing states, his first lead in five waves of interviewing in those states.
The movement toward Obama is essentially due to independents' changing preferences, because Democrats' and Republicans' preferences have been highly stable. Since October, Obama has averaged an 87% to 10% lead over Romney among swing-state Democrats, while Romney has averaged a 90% to 6% lead over Obama among swing-state Republicans.
Independent Women Lead Charge to Obama
Obama's standing against Romney has improved substantially in the swing states among women. Among independents, he has gained among both men and women, but more so among women. In combined data from October and December 2011, Obama trailed Romney by 11 percentage points among independent men and five points among independent women. In combined data from February and March, Obama has a one-point advantage among independent men and a 14-point advantage among independent women.
A closer look at the data in the previous table reveals that Obama's share of the vote has increased by eight percentage points among both independent men and women in swing states since last year. As would be expected, Romney's share of the vote has correspondingly decreased, but it has dropped significantly more among women (11 points) than among men (four points).
It is unclear how much of an impact the recent controversy over government policies toward contraception has had in the loss of support for Romney among independent women. Eight in 10 independent women in the swing states said they were not familiar with Romney's position on contraception, but those who were familiar disagreed with it by a 2-to-1 ratio. Independent women were more likely to have an opinion about Obama's views on contraception (58% were unfamiliar), and were divided about evenly between saying they agree or disagree with them.
Independent voters in the most competitive states may be the quintessential swing group, perhaps holding the key to victory for either Obama or his Republican opponent. Since last fall, their support has shifted toward Obama over his likely Republican opponent Romney, after previously favoring Romney. And it is those independent voters -- particularly women -- who are driving Obama's overall lead in swing states.
So while both campaigns will make considerable efforts to make sure their core supporters vote, the other big piece of their strategy would be finding the issues or themes that help win over independents in the states where either candidate has a reasonable chance of winning.
Sign up to get Election 2012 news stories from Gallup as soon as they are published.
Results for this USA Today/Gallup poll are based on telephone interviews conducted March 20-26, 2012, on the Gallup Daily tracking survey, with a random sample of 933 registered voters, aged 18 and older, living in Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, Virginia, and Wisconsin. The data represent a subset of Gallup's national daily tracking survey for those dates. The swing-state data are weighted to be demographically representative of the combined population in those 12 states.
For results based on the total sample of 371 swing-state independent registered voters, one can say with 95% confidence that the maximum margin of sampling error is ±6 percentage points.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each sample includes a minimum quota of 400 cell phone respondents and 600 landline respondents per 1,000 national adults, with additional minimum quotas among landline respondents by region. Landline telephone numbers are chosen at random among listed telephone numbers. Cell phone numbers are selected using random-digit-dial methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted by gender, age, race, Hispanic ethnicity, education, region, adults in the household, and phone status (cell phone only/landline only/both, cell phone mostly, and having an unlisted landline number). Demographic weighting targets are based on the March 2011 Current Population Survey figures for the aged 18 and older non-institutionalized population living in U.S. telephone households. All reported margins of sampling error include the computed design effects for weighting and sample design.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
For more details on Gallup's polling methodology, visit www.gallup.com.