Mitt Romney has attacked US president Barack Obama for failing the American people and accused him of dragging "the soul of America" toward a "European-style welfare state.
Speaking to a crowd of several hundred people at a peanut warehouse, Mr Romney did not mention new data showing that the country added 200,000 jobs in December, sending the unemployment rate to its lowest level in three years.
The better-than-expected jobs data was released just moments before Mr Romney took the stage in South Carolina.
"We're taking it back!" Mr Romney said of the White House, flanked by governor Nikki R. Haley of South Carolina and Senator John McCain of Arizona, who won the state in 2008.
Mr Romney continued his criticism of Obama's leadership, adding: "This president doesn't understand how the economy works…It's time to get a president who does."
In a statement, the White House said the employment report "provides further evidence that the economy is continuing to heal from the worst economic downturn since the Great Depression."
In New Hampshire, Mr Romney's rivals are sharpening their attacks against him and intensifying their appeals to voters as they try to slow his march toward the Republican nomination.
A new poll suggests that while Romney remains well in the lead in New Hampshire, his rival Rick Santorum is gaining support.
In a 7 News/Suffolk University tracking poll, 40 per cent of likely voters said they planned to vote for or leaned toward Romney, 17 per cent backed Ron Paul and 11 per cent choose Mr Santorum.
In a television appearance yesterday evening, Newt Gingrich savaged Romney's record in Massachusetts, accusing him of appointing liberal judges, raising taxes and allowing abortions to be financed in the health care law he pushed through in the state.
"Governor Romney will not be able to hide behind negative ads," Mr Gingrich said on Fox News.
He added, "People will go, 'Oh yes, that's not somebody I want to be the Republican nominee."'
Jon Huntsman, a former Utah governor, also took aim at Mr Romney at an event last night as he tried to jump-start his struggling campaign.
"The establishment is teeing up Mr. Romney as their choice," said Mr Huntsman, who received the endorsement of The Boston Globe. "The people of New Hampshire will not be told for whom to vote. The people of New Hampshire do not want a coronation."
Referring to Mr Romney as "landslide Mitt," a reference to his razor-thin win in the Iowa caucuses on Tuesday, Mr McCain, who lost to Mr Obama in the 2008 election, said: “It's going to come down, my friends, as it always does, to South Carolina. Whoever gets out their vote is going to win. And we're not taking a single vote for granted.
"This is going to be a very, very close South Carolina election," Mr McCain continued. "If Mitt Romney wins here, he will be the next president of the United States."
New York Times