49-46 Obama (likely voters)
51-43 Obama (registered voters)
This poll was conducted by telephone from September 8-12, 2012 among 1,301 adults nationwide, including 1,170 registered voters. The sample size for likely voters is 1,162. Not all likely voters are assigned the same probability of voting. Phone numbers were dialed from samples of both standard land-line and cell phones. The error due to sampling for results based on the entire sample, the sample of registered voters, and the sample of likely voters could be plus or minus three percentage points. The error for subgroups may be higher. Percentages may not add to 100% due to rounding. This poll release conforms to the Standards of Disclosure of the National Council on Public Polls.
http://www.cbsnews.com/8301-250_162-57512739/poll-obama-leads-romney-39-percent-say-country-is-worse-off-than-four-years-ago