Democratic presidential hopeful Bernie Sanders has won the New Hampshire primary, a key contest in the campaign to become the party’s nominee for president, for a second time.

With 95 per cent of precincts reporting, Mr Sanders attracted 26 per cent of the vote. He is the first Jewish candidate to win the contest twice.

He first won the poll in 2016, where he attracted 60 per cent of the vote against rival Hillary Clinton.

Mr Sanders’ smaller vote share on the 2016 result is on the backdrop of a much more crowded field of democratic candidates.

“This victory here is the beginning of the end for Donald Trump,” Mr Sanders told a rally in Manchester, New Hampshire.

He added he wanted to build an “unprecedented multi-generational, multi-racial political movement” to defeat the Republican.

Mr Sanders now has nine of the 24 New Hampshire delegates, who will assemble at the Democratic National Eonvention in July to elect the party’s nominee for president.

President Donald Trump took to Twitter to mock Mr Sanders and Democrat rival Pete Buttigieg, who also won 24.4 per cent of the vote and nine delegates, saying: “Bootedgeedge (Buttigieg) is doing pretty well tonight. Giving Crazy Bernie a run for his money. Very interesting!”