Perry has toned down his rhetoric, abandoning the use of "vulture capitalism" to criticise Romney, and the Republican National Committee has urged the attacks to stop.

Gordon had also criticized Romney in the 2008 Republican primary campaign, stating that Alabama voters "want a president with Alabama values, not Massachusetts values."

Gingrich, forever in search of "new ideas," seemed to have found one, belatedly, in Iowa: criticize Romney, paying him back for the devastating advertisements sponsored by Restore Our Future, a pro-Romney political action committee.

They showed interviews with its union workers who had been fired and who criticized Romney for the loss of their jobs, with one saying, "I don't think Romney is creating jobs because he took every one of them away."

Mr Huntsman, for his part, on Saturday night criticised Romney in Chinese, probably the first time a candidate has done so.

However, some social conservatives and evangelicals criticize Romney for not being Mormon enough, regarding social policy.

In 2007, it was reported that Ingrid Newkirk, president of the People for the Ethical Treatment of Animals (PETA), criticized Romney about this incident.

Huntsman (rightly) criticized Romney last night in the debate for pandering to the audience about China.

Previously, Huckabee had criticized Romney for claiming to have been a hunter.

Journalists were naturally keen to find out why, after criticising Romney so strongly in earlier public forums, Huntsman now believed he was the best candidate.