Washington: New Jersey Governor Chris Christie and former business executive Carly Fiorina ended their presidential campaigns on Wednesday, narrowing the field challenging front-runner Donald Trump in the race for the 2016 Republican nomination.
Christie, 53, said in a Facebook post he was leaving the race "without an ounce of regret," a day after the combative Republican's sixth-place finish in the New Hampshire primary raised doubts about his viability as a candidate.
Chris Christie quits presidential race
New Jersey Governor Chris Christie bows out of the US presidential race after dismal showings in Iowa and New Hampshire.
Fiorina, 61, a former Hewlett-Packard chief executive, said in a Facebook post she would suspend her campaign. The only woman in the Republican field placed seventh in New Hampshire, one of a series of state-by-state nominating contests for the November 8 election to succeed Democratic President Barack Obama.
Trump's remaining opponents, most of them mainstream Republicans, will likely benefit from their departures, which leave seven Republicans from a field that once had 17 candidates.
Christie had poured much of his campaign's resources into New Hampshire and had considered a good showing there critical. He won only about 7 per cent of votes on Tuesday, despite a pugnacious performance at a Republican debate last weekend.
Trump, a billionaire real estate mogul and former reality TV star, has dominated the Republican race and easily won the party primary in New Hampshire on Tuesday on a wave of voter anger at traditional US politicians.
US Senator Bernie Sanders of Vermont, a democratic socialist, defeated former Secretary of State Hillary Clinton in the state's Democratic contest.
The results testified to the sizable share of American voters upset over the slow economic recovery, immigration and America's place in the world and who are willing to shake up Washington.
Trump's victory showed pundits were wrong to think he would quickly self-destruct based on his penchant for insults and imprecise plans for the presidency. He had lost last week to US Senator Ted Cruz of Texas in the first nominating contest, the Iowa caucuses.
The odds of Trump winning the White House, once seen as an extremely long shot, improved significantly after his victory in New Hampshire, online betting site Ladbrokes PLC said.
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Trump is now at 9/2, compared with 7/1 last week, meaning his chances of victory in November are now 18 percent. Clinton still had the best odds of becoming president at 50/50, Ladbrokes said.
Trump's remaining rivals are still splintered.
Ohio's Republican governor, John Kasich, finished second in New Hampshire, followed by Cruz, former Florida Governor Jeb Bush and US Senator Marco Rubio of Florida.