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The Obama campaign's sustained attack on Mitt Romney's Bain Capital record is driving a divide in the Democratic Party, with former Pennsylvania Gov. Ed Rendell becoming the latest Obama ally to criticize it as others double down on the strategy.

All the while, the White House may be encountering a mounting message discipline problem, with both sides of that divide now spouting commentary that's not exactly on the talking points memo.

Democratic South Carolina Rep. James Clyburn, in an attempt to back up the Obama campaign, went so far Tuesday as to claim Bain was "raping" other companies.

"There is something about raping companies and leaving them in debt and setting up Swiss bank accounts and corporations and businesses in the Grand Caymans. I have a real serious problem with that," Clyburn told MSNBC.

The Obama campaign quickly distanced itself from that remark.

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    "We strongly disagree with Congressman Clyburn's choice of words -- they have no place in this conversation," Obama campaign spokeswoman Lis Smith said, while still urging Romney to "come clean about his record as a corporate buyout specialist."

    Clyburn's comments came after President Obama defended the Bain criticism during a Monday press conference on the sidelines of the NATO summit in Chicago.

    Yet other business-minded Democrats continue to speak out.

    “I think they’re very disappointing,” Rendell said of the Obama campaign ads on Bain, which Romney started and ran before becoming governor of Massachusetts.

    Rendell, Pennsylvania governor from 2003 to 2011, said going after Bain is “fair game,” considering Romney has touted his work at the firm as proof he is better-suited than Obama to revive the struggling U.S. economy.

    “But I think how you examine it, the tone, what you say, is important as well,” he said in an interview with BuzzFeed.

    The intra-party backlash started Sunday when Newark Mayor Cory Booker criticized the attacks. He and others maintain private-equity firms such as Bain Capital are essential in providing cash to help businesses grow and create more jobs in the down economy -- though, as Romney has said, there were failures along the way.

    There's also the underlying concern that attacking a key player in reviving the U.S. economy and a deep-pocketed campaign contributor might not be the best political strategy.

    On Tuesday, Virginia Democratic Sen. Mark Warner, who made a fortune as a venture capitalist before becoming a politician, delivered a similar, nuanced message.

    “I think Bain Capital was a very successful business,” he said on MSNBC. “They got a good return for investors. That is what they are supposed to do.”

    However, Warner argued the jobs of president and investor each have different “skill sets” and “time horizons” -- with an elected official responsible for long-term solutions compared to short-term profits.

    On Monday, former Democratic Tennessee Rep. Harold Ford said he agreed with the “substance” of Booker’s comments.

    The comments were accompanied by those of financier and former Obama economic adviser Steve Rattner, who said Bain Capital “need not be embarrassed” about its record. The comments were later strung together for a Romney web video that highlighted the internal Democratic dissension over the Bain talking points.

    Still, the Obama team, which released a new Bain video Monday, is trying to bring the party back in line. Booker released a web video after his Sunday interview walking back his remarks. He said Romney, the presumptive GOP presidential candidate, has touted himself as a jobs creator and encouraged the Obama campaign to examine that record and discuss it.

    Obama kept up the message drumbeat Tuesday, tweeting out: "POTUS on why Romney economics matters: As president, 'Your job is to figure out how everybody has a fair shot.'"