Republican presidential hopeful Mitt Romney has conceded he he has "an uphill climb" in the next primary in South Carolina, where he finished fourth in 2008.
But after initial victories in Iowa and New Hampshire Mr Romney told CBS's "This Morning" he was confident about South Carolina, saying "I know we're going to push forward."
He voiced regret that his fellow Republicans have made his record as a venture capitalist an issue, but said it is not having any effect. He said, "They tried the same line here in New Hampshire and it fell extremely flat."
Mr Romney said he has a record of starting businesses and creating tens of thousands of jobs. And he said that if elected, he would not hesitate to apply his business experience in an all-out campaign to shrink the size of the federal government.
rougher tone and a tougher ideological terrain await the former Massachusetts governor in South Carolina where evangelicals make up the base of the Republican Party. His rivals are banking on that to stop him in his tracks, while he is looking to force them from the race with a four-state winning streak that takes in Florida 10 days later.
He posted a double-digit win in New Hampshire after winning by just eight votes the week before in Iowa. His victory was expected; Mr Romney is the former governor of the neighbouring state of Massachusetts, has a holiday home in New Hampshire and is a frequent visitor to the state.
Mr Romney got 39% of the vote, a 16% advantage over his closest challenger, Texas congressman Ron Paul. A win in South Carolina primary and then Florida could make Mr Romney all but unstoppable.
Because of his appeal to independent voters, Mr Romney could be the toughest potential rival for President Barack Obama, whose popularity has fallen because of the slow US recovery from recession. Exit polls showed the economy was the biggest issue in New Hampshire, as it has been nationwide.
Meanwhile, the three candidates most likely to draw conservative voters - Newt Gingrich, Rick Santorum and Rick Perry - have been struggling.
All the candidates planned to campaign on Wednesday in South Carolina.TV adverts already are filling the South Carolina airwaves, including negative spots like the new one from Mr Gingrich assailing Mr Romney for switching his position on an issue that resonates strongly with evangelicals. "He governed pro-abortion," the Gingrich ad says. "Massachusetts moderate Mitt Romney: He can't be trusted."