WASHINGTON -- Democrats repeatedly attacked Mitt Romney for his secretive offshore financial arrangements on Sunday, on the heels of a major Vanity Fair story detailing the presumptive Republican presidential nominee's Swiss bank account and various holdings in the Caribbean.

"He is the first and only candidate for U.S. president with a Swiss bank account, with tax shelters," Sen. Dick Durbin (D-Ill.) said on CBS' "Face the Nation." "There is just no way to explain it."

Although Romney has closed the Swiss bank account and insists he paid normal U.S. taxes on all of his financial arrangements, both he and his GOP allies have had trouble explaining why Romney orchestrated such complex financial holdings in secretive tax-haven nations.

Mississippi Gov. Haley Barbour (R), also appearing on "Face the Nation," did not respond directly to Durbin's discussion of Romney's tax status, shifting the discussion to President Barack Obama's economic record, and the weak economic recovery.

Appearing on ABC's "This Week," Louisiana Gov. Bobby Jindal (R) countered criticism of Romney's financial holdings by attempting to associate them with his career in private equity.

"In terms of Governor Romney's financial success," Jindal said, "I'm happy that he's a successful businessman."

Maryland Gov. Martin O'Malley (D), appearing with Jindal, repeatedly castigated Romney over the issue.

"Mitt Romney bets against America," O'Malley said. "He bet against America when he put his money in Swiss bank accounts and tax havens and shelters and also set up a secret company, the shell company in Bermuda, which, by the way, in order to avoid disclosure, he put in his wife's name right before he became governor of Massachusetts."

The Vanity Fair article was written by Nicholas Shaxson, whose book about tax havens, "Treasure Islands," is considered a classic by many tax policy experts. Shaxson reported that it is extremely difficult to discern exactly how much money Romney stashed in the Cayman Islands, Bermuda and Switzerland, because these jurisdictions are notoriously secretive, affording wealthy individuals and corporations broad protections from U.S. tax authorities.

On "Fox News Sunday," Rep. Debbie Wasserman Schultz (D-Fla.), chairwoman of the Democratic National Committee, argued that Romney has been unnecessarily secretive about his financial holdings, noting that he has only released one year's worth of tax returns. While Romney has released only his 2010 tax returns and an estimate for his 2011 filing, his own father, George Romney, disclosed 12 years' worth of data when he ran for president in the 1960s. Obama, meanwhile, has released tax records dating back to 2000.

"I'd really like to see Mitt Romney release more than one year of tax records because there's been disturbing reports recently that he's got a ... secretive Bermuda corporation that no one knows anything about, investment in the Caymans," Wasserman Schultz said. "Americans need to ask themselves: why does an American businessman need a Swiss bank account, and secretive investments like that?"

The Romney campaign pushed back against the criticism in a statement e-mailed to HuffPost. "Mitt Romney had a successful career in the private sector, pays every dime of taxes he owes, has given generously to charitable organizations, and served numerous causes greater than himself," said Romney spokeswoman Andrea Saul.

Story updated to include comment from Romney campaign.

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  • Steven Lund

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  • Robert Mercer

    Robert Mercer, left, Renaissance Technologies (Financial)

  • John Paulson

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  • Julian Robertson

    Julian Robertson, Tiger Management (Hedge Fund)

  • Paul Singer

    Paul Singer, right, of Elliot Management (Hedge Fund)

  • Melaleuca

    Melaleuca and owner Frank VanderSloot (Personal Care)

  • Paul & Sandra Edgerley

    Paul & Sandra Edgerley, Bain Capital

  • Bob Perry

    Bob Perry, Perry Homes (Home Builder)

  • Francis Rooney

    Francis Rooney, Rooney Holdings (Financial)

  • Oxbow Corp. and William Koch

    Oxbow Corp. and owner William Koch (Energy & Technology)