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Vice President Biden drew a tough retort from Mitt Romney's campaign Tuesday after telling a Virginia audience that the Republican presidential candidate's plan to lift financial regulation would "put y'all back in chains."

Romney's campaign responded by claiming the rhetoric marked a "new low" in the 2012 race.

Biden made the remarks during a stop in Danville, Va. He took a swipe at Romney's plan to ease financial regulations, by recycling a Romney bank analogy and creating an analogy of his own.

"He said in the first 100 days, he's going to let the big banks once again write their own rules," Biden said. "Unchain Wall Street! They're gonna put y'all back in chains."

The remark's context is unclear. Some conservative blogs claimed Biden had just made a reference to slavery. Danville, aside from being the last capital of the Confederacy, is racially split -- the city is nearly half black and half white. The crowd at Tuesday's event reflected that makeup.

Romney campaign spokeswoman Andrea Saul fired back at Biden after the event, without accusing Biden of any racial reference.

"After weeks of slanderous and baseless accusations leveled against Governor Romney, the Obama campaign has reached a new low," she said. "The comments made by the vice president of the United States are not acceptable in our political discourse and demonstrate yet again that the Obama campaign will say and do anything to win this election. President Obama should tell the American people whether he agrees with Joe Biden's comments."

The Obama campaign, though, likened the language Biden used to language used repeatedly by GOP officials.

"For months, Speaker Boehner, Congressman Ryan and other Republicans have called for the 'unshackling' of the private sector from regulations that protect Americans from risky financial deals and other reckless behavior that crashed our economy," Stephanie Cutter, deputy campaign manager, said in a statement. "Since then, the vice president has often used a similar metaphor to describe the need to 'unshackle' the middle class.

"Today's comments were a derivative of those remarks, describing the devastating impact letting Wall Street write its own rules again would have on middle class families. We find the Romney campaign's outrage over the vice president's comments today hypocritical, particularly in light of their own candidate's stump speech questioning the president's patriotism. Now, let's return to that 'substantive' debate Mitt Romney and Paul Ryan promised 72 hours ago, but quickly abandoned."

Biden on Tuesday was specifically talking about the plank of Romney's economic plan that calls for easing restrictions on financial institutions put in place when the Dodd-Frank banking overhaul took effect in 2010.

Biden didn't limit his attacks to the nation's finances Tuesday.

He continued to jab Romney for only releasing two years of tax returns, again noting the practice of providing more information that was started by Romney's father during his presidential bid.

"And how many people think you can run for president of the United States and not let the American people know what your tax returns are?" Biden asked the audience.

"This is not your father's Republican Party. ... This is not even Mitt Romney's father's Republican Party."

Biden also said Romney's plan to repeal the health care overhaul would take the country back to a time when being a woman is a "pre-existing condition."

That line of attack was teed up by former U.S. Rep. Tom Perriello, D-Va., who warmed up a vocal crowd by equating Romney's running mate Paul Ryan with an unpopular Congress.

"Paul Ryan's Congress that wants to take us back to where being a woman is a pre-existing condition," he said. Perriello represented Virginia's 5th District and was swept out of office in the 2010 midterm election that saw Republicans take control of the House of Representatives.

The attacks came in a town situated near the border of two neighboring swing states, North Carolina and Virginia. Obama won both in 2008 and they are crucial to this year's race.

Though Danville is north of the border in Virginia, Biden seemed to think he was in the Tarheel State as he wrapped up his remarks.

"With you, and I mean this, with you, we can win North Carolina and if we do, we win the election again with you," Biden said.