(NBC NEWS) The Romney campaign ratcheted up its language on Tuesday in a conference call on which former New Hampshire governor and White House chief of staff John Sununu said he wished President Obama “would learn how to be an American.”

Sununu led a series of Romney surrogates in questioning the president’s commitment to economic freedom, dredging up the president’s ties to Tony Rezko; another speaker on the conference call said Obama’s policies were akin to “socialism.”

But it was Sununu’s questioning of whether the president understood how to be an American, even after a subsequent walk-back, that made the call feel like part of a late-October attack, and not a story out of what Sununu called the “summer doldrums.”

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