The Romney campaign is moving swiftly to capitalize on Vice President Biden's comment in Charlotte on Tuesday that the middle class had been "buried" during the past four years.

At a North Carolina campaign event Tuesday, Biden said that Romney would raise taxes on the middle class "How they can justify ... raising taxes on the middle class that has been buried the last four years?" he asked. Of course, Obama was in office when those people were "buried." 

Romney chimed in on Twitter:

And Republican vice presidential candidate Paul Ryan picked up on the remarks at an Iowa rally. 

"We agree!" he said. "That means we need to stop digging by electing Mitt Romney as the next president of the United States."

Romney surrogate John Sununu, told reporters on a conference call that Biden made "a singularly correct observation."

Asked if he thought the vice president's words would move poll numbers, the former New Hampshire governor replied, "No, but I think it sets the stage for the debate that will take place tomorrow." The comment "tells the public this is what you really ought to be looking for" in the debate, he added.

Sununu added that the Denver debate is a chance for Romney to introduce himself anew. "A great deal of America has never seen Governor Romney except through news clips,” he said.