Republican Donald Trump and Democrat Bernie Sanders coasted to victory on a wave of voter anger in the New Hampshire presidential nominating contest, thrashing traditional US politicians in a display of anti-establishment power.
Republican contender Marco Rubio struggled at a presidential debate, potentially confounding his bid to emerge as Donald Trump's chief rival in New Hampshire and giving hope to three rivals desperate for a strong showing.
The US presidential race looked suddenly wide open after frontrunners Donald Trump and Hillary Clinton suffered chastening evenings in Iowa, the first step on the long road to the White House.
