The president's reelection campaign is launching its first television ad targeting Mitt Romney's controversial comments about Americans who do not pay taxes.
The ad also says former Gov. Mitt Romney refuses to release his own tax records.
The 30-second spot starts airing in Ohio today.
Romney begins a bus tour in Ohio later this week.
With just over a month to the election, the GOP's presidential nominee says he will now turn his attention to spending more time with voters, and less time raising money.
Romney spent much of the weekend attending fundraisers in California.
He told reporters that Obama's decision in 2008 to bypass traditional spending limits has forced him to spend more time courting donors than he would like.