Pundits are arguing over Biden's use of 'chains' and 'ya'll': racially insensitive or allusive to GOP financial rhetoric?

A prominent Republican has accused vice president Joe Biden of "playing the race card" over remarks suggesting Mitt Romney's plans to loosen bank regulation would put people "back in chains".

Rick Santorum, a conservative who ran against Romney in the primaries but has since fallen behind his party's nomination, led the renewed attack on Sunday by describing the comments as further evidence of dirty tactics by the Obama campaign aimed at pitting Americans against each other.

On Tuesday, Biden told an audience in Virginia, which included African Americans, that less bank deregulation would harm ordinary people.

"They're going to put y'all back in chains," he said.

Santorum said that Biden's use of "y'all" was an inappropriate attempt "to develop an affinity with the group that you are speaking in front of" – taken to mean African Americans, most of whom are descendants of slaves.

"Y'all?" he said. "He tried to develop the affinity and he did it in a horrendous way, and he should apologise for it."

Santorum said that Biden's remarks were indicative of the "divisive" tone of the Obama campaign's attacks on Romney.

"It is one thing to attack him on his record and fair game. Go for it. But to go out and do what he is doing as far as dividing the country, and he is, it is class warfare at its worst," he said.

Rudolf Giuliani, the former New York City mayor, said Biden's comments, on top of a series of other gaffes over recent years, suggested he is not up to the vice presidency and therefore, implicitly, the presidency as the man who would take over the White House if Obama could not serve.

"I mean, there's a real fear is . . . whether he really has the mental capacity to handle it," he said. "I mean, this guy just isn't bright."

The Obama campaign dismissed the attacks as "faux outrage".

The president's deputy campaign manager, Stephanie Cutter, told ABC's This Week that Biden's comments were a direct response to Republican proposals to "unshackle" businesses from government regulation which they blame for a poorly performing economy.

"Let's look at what the vice president actually said. Speaker [John] Boehner, even [Romney's running mate] Paul Ryan have been travelling this country talking about the need to unshackle the private sector, unshackle the financial industry and the vice president was just taking that metaphor a step further and talking about wanting to put other people in shackles,"

Cutter said the issue was not Biden's use of language but the broader point he was making about Romney's call for deregulation of Wall Street and the private sector which would encourage more of the "reckless behaviour" that led to the recent recession.

"They're using that one word as a distraction, but the larger point is an important point," she said. "The president absolutely believes in the free-enterprise system, but we also believe that everybody should play by the same set of rules."

Obama has already defended Biden.

"The truth is that during the course of these campaigns, folks like to get obsessed with how something was phrased even if everybody personally understands that's not how it was meant," he told People magazine. "That's sort of the nature of modern campaigns and modern coverage of campaigns. But I tell you, when I'm traveling around Iowa, that's not what's on people's minds."

But there was also criticism from some Democrats including Maryland's governor, Martin O'Malley who said Biden could have chosen his words more carefully.

"I think it was an indelicate play on the Republican words of shackling the economy with regulations and shackling small businesses," he said on NBC's Meet the Press. "It was certainly an indelicate choice of words."

The Boston Globe newspaper called on Biden to apologise for the comments, saying that if Romney's running mate, Paul Ryan, had made similar comments he "would be pilloried for racial insensitivity — and so would Romney".

"In the fight for civility and substance over pointless hyperbole, Biden may not be the worst offender. But he's an offender nonetheless, and he should apologize," the Globe said in an editorial.

Obama's former spokesman and now campaign adviser, Robert Gibbs, denied that Biden is a "drag on the ticket".

"I'm happy to have Joe Biden out campaigning and telling his story to the American people, putting in front of people the choice that's going to happen in this election," he said. "I'm happy and proud of Joe Biden and I'm happy and proud to have him on the trail every day."