CHESTERFIELD, Va. - Campaigning in the battleground state of Virginia Tuesday, Vice President Biden used Mitt Romney's recently released 2011 tax returns to criticize the GOP nominee for his comments dismissing the 47 percent of voters who do not pay income taxes.

"He attacks the 47 percent of the American people who he says pay no federal taxes. And he attacks, he, Romney? Attacking someone on taxes? I mean, Woah! That's like me attacking someone for being passionate in politics," Biden told a crowd at the Chesterfield County Fairgrounds.

"He really sees it in a totally different way. When he said it's not my job to worry about 'these people,' well whose job is it?" Biden asked the crowd. "Ladies and gentlemen, we are our brother's keeper. We are one nation under God. We are all in this together, and if the 47 percent doesn't make it, the country doesn't make it."

Speaking to a crowd estimated to be over 600 people, Biden knocked the Republican nominee a few days after he released his 2011 tax returns which showed he paid a lower tax rate in 2011 than many Americans whose incomes are far less than Romney's. Biden noted that Romney asked for 10 years of tax returns from his running mate Rep. Paul Ryan during the vetting process, but is unwilling to release the same amount himself.

"Ladies and gentlemen, somebody today in America making $23,000 a year pays over 20 percent of their income in taxes, in some form of taxes. Someone making, a couple making a hundred thousand dollars a year, they pay 29 percent in total tax," Biden said. "Romney paid 14 percent of his income in federal income tax. He made over $13 million in income, almost all from investments which he paid in 17 percent or less… He has millions stashed in tax havens like Bermuda and the Cayman Islands. The guy had a Swiss bank account."

"Instead of attacking folks who work for a living and pay their way, Romney should be respecting their hard work. That's the job of a president: to lift people up, not to tear them down," the vice president added.

Biden tried to appeal to the middle class, which he said was "decimated by the policies that produced this recession," and a group which he accused the GOP ticket of not understanding.

"Middle class is a value set. Middle class is being able to own your home, not just rent it. Middle class values are being able to live in a safe neighborhood. Middle class values mean you can send your kid to a school where they can have a fighting chance to get college, and if they get accepted to college you got a fighting chance of being able to send them to college. It's about being able to help your parents as they get older, and hope you can save enough so your children won't have to help you. That's what middle class means. They just don't understand it," Biden said.

Drawing on his own experience reaching across the aisle with former Sens. Jesse Helms and Strom Thurmond, Biden painted Romney and Ryan as politicians who are unwilling to compromise.

"If you remember in the debates, Governor Romney says and he repeated when asked by moderators would you agree to a plan to significantly reduce the national debt if in fact it had ten dollars in spending cuts for only one dollar in new revenue and he said, 'Yes, I would reject it.' Ladies and gentlemen, these guys think compromise is somehow a dirty word. Ladies and gentlemen, they are insisting and Romney is insisting on putting back in policies that produced the problem in the first place."

With Biden set to debate Ryan in Danville, Ky., next month, a campaign official told ABC News Biden held his first mock debate session last week with Rep. Chris Van Hollen, D-MD, who is playing the role of Ryan in debate prep.

Romney's spokesman Ryan Williams responded to Biden's attacks.

"President Obama and Vice President Biden's reckless policies have increased our national debt by $5.4 trillion and resulted in dangerously high unemployment, increased poverty, and plummeting incomes…. Governor Romney will spur economic growth and create more wealth, while President Obama believes in redistributing wealth. The Romney plan for a stronger middle class will create 12 million jobs and encourage upward mobility instead of more government dependency."