(CNN) - Surrogates for President Barack Obama defended Joe Biden on Sunday from critics who say the vice president's comments last week at an event in Virginia show his unsuitability for the office.
Rudy Giuliani, the Republican former mayor of New York, questioned Biden's "balance" on CBS, saying he wasn't sure Biden would be able to step into the top role if the situation arose.
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"I don't think he's nuts. I'm just saying I wonder if he's got the kind of balance - probably what I should have said is the balance to be president of the United States," Giuliani said. "This guy is like one gaffe after another, and he's a joke on late-night television."
On Tuesday, Biden told a predominantly black crowd in Danville, Virginia, that Mitt Romney's regulatory policies would "put y'all back in chains," a comment that drew near-immediate condemnation from Republicans, who said Biden was inciting racial division.
Obama himself said in interviews this week that Biden was not trying to connote anything aside from an attack on Romney's stance toward Wall Street, telling People magazine that Biden "has been an outstanding vice president."
On Sunday, Stephanie Cutter, Obama's deputy campaign manager, offered a tough rejoinder to Giuliani, who also said earlier this week that Biden has "never been bright."
"I would like to point back to (Guiliani's) glowing introduction of Sarah Palin during the 2008 convention," Cutter said on ABC. "So if he wants to criticize the capacity of the vice president to take hold of this country, he should go back and look at those remarks and whether he still believes that they're true."
Robert Gibbs, an Obama campaign adviser, made a similar argument on Fox News, saying Biden's remarks were no more "racial" than similar rhetoric from Republicans.
"No more race-baiting than when John Boehner says let's unshackle Wall Street," Gibbs said of Biden's remarks.
And Maryland Gov. Martin O'Malley, a Democrat, said on NBC "there's not a racist bone in Joe Biden's body," though he conceded that the vice president could have chosen a better word.
"I think it was an indelicate play on the Republican words of shackling the economy with regulations and shackling small businesses, and so it was certainly an indelicate choice of words," O'Malley said.
CNN's Kevin Liptak contributed to this report.
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