COLUMBIA, S.C. — For the Republican presidential candidates who want to stop Mitt Romney in South Carolina, it comes down to this: How far are they willing to go?
A day after Mr. Romney’s victory in New Hampshire left his rivals running out of time to block his path to the nomination, he was greeted here by a wave of attacks on his business record, his past support for abortion rights and his character.
With little left to lose, Newt Gingrich,Gov. Rick Perry of Texas and their allies sought to portray Mr. Romney as insufficiently steadfast in his conservatism in this very conservative state, threatening a scorched-earth approach to the primary to be held here on Jan. 21.
But there were some signs that a pressure campaign from the party establishment — encouraged and to some degree organized by pro-Romney forces — was forcing his rivals to recalibrate if not rethink the attacks. A growing chorus of high-profile Republicans criticized the attacks on Mr. Romney’s earlier career buying and selling companies as Democratic talking points.
Two days after former Gov. Jon M. Huntsman Jr. of Utah said that Mr. Romney “likes firing people,” The Associated Press reported him as saying on Wednesday: “If you have creative destruction in capitalism, which has always been part of capitalism, it becomes a little disingenuous to take on Bain Capital,” Mr. Romney’s former firm.
But Mr. Gingrich said he would not back off as an outside “super PAC” supporting him introduced a scathing video about Mr. Romney’s work at Bain. And Mr. Perry kept up his critique of what he has called Mr. Romney’s “vulture capitalism.”
It was Day 1 of what is shaping up as a 10-day test of whether conservatives can marshal the arguments, tactics and unity to slow Mr. Romney and rally around a single alternative — and of whether Mr. Romney, now in a commanding position, can show the muscle needed to stamp out the opposition and take control of the party.
Mr. Romney utilized the full force of his formidable campaign machinery to create a backlash against the attacks on his record at Bain. Employing resources no other campaign can match, his Boston headquarters held conference calls with his huge array of endorsers around the nation, sent talking points to supporters and enlisted go-betweens to tell leaders of the pro-Gingrich group Winning Our Future that they were harming the party with the attacks.
At the very least, Mr. Romney’s team appeared to have made headway in casting his opponents as abandoning their own party’s longstanding support for the free market. It received backing Wednesday from two political voices that have had the respect of the Tea Party movement here in ways Mr. Romney has not: Gov. Nikki R. Haley of South Carolina, who has endorsed Mr. Romney, and Senator Jim DeMint, who has not.