Mr. Romney’s own words have stoked the rivals’ fires, giving Democrats more grist. Republicans mocked him for telling New Hampshire voters that he, too, has feared “pink slips,” calling the claim implausible for the Harvard-educated son of a multimillionaire governor. And they pounced on his statement, captured on videotape, that “I like being able to fire people,” though they took it out of context since he was complaining about companies that do not provide good service, specifically insurance companies.

The sudden intraparty assault has helped Mr. Romney in one way, prompting even conservative skeptics like Rush Limbaugh to come to his defense. The conservative Club for Growth singled out Newt Gingrich for “economically ignorant class warfare rhetoric” that is “downright Obamaesque.”

Mr. Gingrich persisted in South Carolina on Wednesday. “I am for entrepreneurship,” he said, “but I am also for the American people’s right to understand how the games are being played: Are they fair to the American people, or are the deals being cut on behalf of Wall Street institutions and very rich people?”

A “super PAC” supporting Mr. Gingrich plans ads depicting Mr. Romney as a corporate raider “more ruthless than Wall Street.” Gov. Rick Perry of Texas, making his last stand in South Carolina, again on Wednesday cited job losses at a local plant that Bain shut down.

“I understand the difference between venture capital and vulture capitalism,” he said.

Jon M. Huntsman Jr., a former governor of Utah, and Representative Ron Paul have also piled on. Only former Senator Rick Santorum has not. “I just don’t think as a conservative and someone who believes in business that we should be out there playing the games that the Democrats play, saying somehow capitalism is bad,” he said on Fox Tuesday.

The controversy is encouraging to Democrats as they weigh Mr. Obama’s re-election prospects in a year when the weak economy is the main issue. It can only help, their thinking goes, if the most likely Republican nominee emerges from the race as a representative of — in Mr. Axelrod’s words — “everything that people hate about this economy.”