Meanwhile, new Republican-leaning independent groups have entered the presidential advertising fray as polling suggests Romney's campaign may be losing ground against Obama in key states such as Ohio and Florida.
The commercials, aimed at voters who supported Obama in 2008 but are now undecided, join those from the campaigns and outside groups swamping a narrow and possibly shrinking map of competitive states in the fast-moving presidential contest. Americans for Job Security launched an $8.7 million ad buy in six battleground states, while the Ending Spending Action Fund, a new conservative group bankrolled by billionaire Joe Ricketts, was set to debut a $10 million, four-state ad campaign on Thursday.
Obama supporters also are working to keep Romney's "47 percent" comments alive. Democratic super PAC Priorities USA Action and a political group tied to the American Federation of State, County and Municipal Employees released a radio ad in Ohio and Virginia airing the remarks. The ad, part of a $1.25 million radio buy, tells listeners Romney's "just not looking out for us."
Pickler reported from Washington. Associated Press writer Matthew Daly in Virginia and Beth Fouhy in New York contributed to this report.