Romney has refused so far to disclose many of the details to support his assertion that his proposal would not lead to a tax cut. His ad was an attempt to parry a report by the Tax Policy Center that Obama has frequently tried used to political advantage, as he did again during the day.
In a new ad by the president's campaign, Romney is quoted as saying that a $5 trillion tax cut "is not my plan." The ad then cites a study by the Tax Policy Center as saying it is, and asks why the Republican challenger "won't level with us about his tax plan which gives the wealthy huge new tax breaks.
"Because if we can't trust him here" — a photo of the debate stage appears — "How could we ever trust him here," the narrator says as a photo of the Oval Office fills the screen.
The two men debate twice more this month, Oct. 16 in Hempstead, N.Y. and Oct. 22 in Boca Raton, Fla.
Before they do, Vice President Joe Biden and Romney's running mate, Wisconsin Rep. Paul Ryan, will share a stage in Danville, Ky. in one week's time.
Biden plunged into the tax debate during the day, saying the administration does indeed want to increase the taxes paid by the wealthy by $1 trillion.
"We want to let that trillion-dollar tax cut expire so the middle class doesn't have to bear the burden of all that money going to the super wealthy," he said while campaigning in Iowa. "That's not a tax raise, that's called fairness where I come from."
Republicans didn't see it that way, and seized on the comment as evidence the administration's policies would kill jobs.