Bernie Sanders' landslide victory in Nevada's Democratic nominating contest has scattered his moderate challengers and injected his White House campaign with a fresh burst of momentum as he drives into the next crucial battlegrounds.

With his strong result yesterday, the Vermont senator demonstrated an ability to broaden a coalition beyond the narrow limits of leftist voters, undercutting the argument from several moderates that he would not be able to bridge the divide between progressives and centrists.

"He showed last night that he can energize our core base," Howard Dean, a former presidential aspirant himself and former head of the Democratic National Committee, told CNN.

By early Sunday, Mr Sanders was comfortably ahead in Nevada with 60% of precincts reporting.

The 78-year-old senator was leading the Democratic pack with 46% of the vote, followed far behind by former vice president Joe Biden at 19.6% and Pete Buttigieg, the former mayor of South Bend, Indiana, at 15.3%.

Senators Elizabeth Warren and Amy Klobuchar trailed at, respectively, 10.1% and 4.8%.

Mr Sanders was quick to claim victory, saying his "multi-generational, multi-racial coalition" was "going to sweep this country."

Mr Dean said the senator's result in a state far more typical of America's demographic variety than the two earlier-voting states was "incredibly impressive."

But he quickly added that a more definitive result will come only after voters in 14 states cast ballots on 3 March, or "Super Tuesday."

Before that comes South Carolina, which votes on 29 February.

Mr Biden's once-strong prospects had faded sharply for weeks, but he said yesterday that he felt "really good" about his second-place showing in Nevada and should not be counted out.

His team is banking on a strong showing in South Carolina, where Mr Biden has enjoyed support among a majority-black Democratic electorate.

But after Mr Sanders came in virtually tied for first in Iowa and then won last week in New Hampshire, his undeniable victory in Nevada places him squarely in the driver's seat, at least for now.

He leads national polls by an 11 point margin over Mr Biden and by 13 points over Mike Bloomberg, the former New York mayor who skipped the early voting states to focus on Super Tuesday.

Mr Sanders's progressive policies, including universal health care, higher taxes on the wealthy and an increase in the minimum wage, have struck a chord with millions of Americans.

But they have raised alarm among some Democrats that he will make an easy target for US President Donald Trump as a radical leftist, and that if he heads the Democratic ticket in November the party could face sweeping losses.

Yesterday Mr Trump issued a sarcastic-sounding congratulations on Twitter to the man he calls "Crazy Bernie."

Asked if the Democrats' majority in the House of Representatives might be threatened if Mr Sanders turned out to be Mr Trump's rival in November, one powerful South Carolina Democrat said that it might.

It "would be a real burden for us in these states or congressional districts that we have to do well in," said James Clyburn, the House Democratic whip.

"In those districts, it's going to be tough to hold onto these jobs if you have to make the case for accepting a self-proclaimed Democratic socialist."

Mr Buttigieg, while congratulating Mr Sanders on his Nevada victory, offered a stern warning against picking someone who he said sees "capitalism as the root of all evil" to go up against the populist president.

Pressure seems certain to grow on some of the lower-polling Democratic moderates to withdraw to allow others to coalesce around a centrist who might fare better against Mr Trump.

Republican campaign advisor Mark McKinnon, speaking on CNN, predicted that the lower polling candidates will be flushed out of the race after Super Tuesday.