US Democratic presidential contender Bernie Sanders has won nominating contests in Alaska, Washington and Hawaii, chipping away at frontrunner Hillary Clinton's lead in the race to pick the party's candidate for the White House.

Sanders' wins on Saturday underscored Clinton's vulnerabilities within her own party, particularly with young voters and liberal activists who have been inspired by her rival's left-of-centre message.

In an interview with the Associated Press news agency, Sanders cast his performance as part of a Western comeback, saying he expected to close the delegate gap with Clinton as the contest moved to the more liberal northeastern states, including her home state of New York.

He also said his campaign was increasing its outreach to superdelegates, the party insiders who can pick either candidate, and who are overwhelmingly with Clinton.

"The Deep South is a very conservative part of the country," he said. "Now that we're heading into a progressive part of the country, we expect to do much better."

He added: "There is a path to victory." With Clinton far in front, however, it is a difficult path.

Clinton eyes New York

Clinton anticipated the losses. She barely campaigned in the three Western states, making one day of stops in Washington state.

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She is turning her focus to the April 19 contest in New York, seeking to win a large share of the delegates at stake and to avoid the blow of losing to Sanders in a state she represented in the Senate.

She is trying to lock up an even larger share of delegates in five northeastern state contests a week later, hoping to deliver a big enough haul to unify the Democratic Party and relegate Sanders to little more than a protest candidate.

Sanders, who has found some success in the industrial Midwest, wants to leverage his arguments against free trade and his working-class support into an April 5 victory in delegate-rich Wisconsin.

He also plans to compete fiercely in New York and is pushing for the party to schedule a debate in the state, saying it would be "really absurd" if one did not take place.

'We're going to win'

On Saturday, he told more than 8,000 cheering supporters at a rally in Madison, Wisconsin, that his campaign had momentum, citing Saturday's wins that followed recent victories in Utah and Idaho.

"Don't let anybody tell you we can't win the nomination or we can't win the general election. We're going to do both of those things."


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After Sanders' two wins in Alaska and Washington on Saturday, Clinton held a delegate lead of 1,234 to 956 over Sanders, according to an Associated Press analysis, an advantage that expands to 1,703-985 once the superdelegates are included.

It takes 2,383 delegates to win the nomination at the party's national convention in July in Philadelphia.

Based on the AP count, Sanders still needs to win more than 57 percent of the remaining delegates from primaries and caucuses to have a majority of those delegates by the end of June.

His bar is even higher when the party officials are considered. He needs to win more than 67 percent of the remaining delegates overall - from primaries, caucuses and the ranks of uncommitted superdelegates - to prevail.

Source: Agencies