Bernie Sanders wins West Virginia Democratic primary

White House dreams fading, Bernie Sanders added another state to his tally against Hillary Clinton with a win in West Virginia on Tuesday — a victory that will do little to slow the former secretary of state's steady march toward the Democratic presidential nomination.

Meanwhile, Republican Donald Trump also won there and in Nebraska, a week after he cleared the field of his remaining rivals. They were not victories likely to heal the party's wounds, as some GOP leaders continue to hold off offering their endorsement of the party's presumptive nominee.

Clinton was projected to win Nebraska's primary Tuesday. But the Nebraska's Democrats caucused in March — giving Sanders a comfortable win over Clinton.

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The result in the West Virginia Democratic primary underscored the awkward position Clinton and the party's establishment face as they attempt to turn their focus to the general election. Sanders has won 19 states to Clinton's 23, but she is 94 per cent of the way to winning the nomination — just 145 delegates short of the 2,383 required.

That means she could lose all the states left to vote by a landslide and still emerge as the nominee, so long as all her supporters among the party insiders known as superdelegates continue to back her.

Clinton needs to win just 14 per cent of the delegates and uncommitted superdelegates at stake in the remaining contests, and she remains on track to capture the nomination in early June.

Still, Sanders is vowing to fight on. He campaigned in Oregon and California on Tuesday and his victory in West Virginia highlighted anew Clinton's struggles to win over white men and independents — weaknesses Trump wants to exploit in the fall campaign.

"Let me be as clear as I can be, we are in the campaign to win the Democratic nomination," Sanders said at a campaign event in Salem, Ore. "We are going to fight for every last vote."

While Sanders is still attracting thousands to rallies, his campaign has grown harder as Clinton closes in on the nomination. His fundraising has fallen off and so, too, has his advertising, with only about $525,000 US in ads planned for California and $63,000 each in West Virginia and Oregon, according to advertising tracker Kantar Media's CMAG.

That's a significant decline from the wall-to-wall advertising campaign he ran earlier in the primary, during which his $74 million in ads outspent Clinton by $14 million.

In West Virginia's mixed primary system, less than six in 10 of those voting said they're Democrats.

The exit polls also illuminated another bloc of voters: those who voted for Sanders on Tuesday but would abandon him if he faced Trump in November.

About a third of West Virginia Democratic primary voters would choose Trump in general election matchups with either Sanders or Clinton.

Trump hopes to build on wins in the general

Edward Milam, of Cross Lanes, W.Va., is a self-described socialist who gave money to the Sanders campaign but his vote Tuesday to Clinton.

"After about six-seven months of debating and watching, I think Hillary has a lot more to offer than Bernie internationally," the 68-year-old retiree said. "I think she handles herself well. I've known about her for 30 years, just like everybody else has. I don't think there will be any surprises."

Even as the primaries continue, Clinton has largely shifted her focus to the general election. On Monday, she courted suburban women in Virginia and on Tuesday, in Lexington, Ky., she released a proposal to ensure families don't spend more than 10 percent of their income on child care.

"I don't care about what he says about me," she said of Trump in Louisville, Ky., on Tuesday night. "But I do resent what he says about other people, other successful women, women who have worked hard, women who have done their part."

Clinton's campaign hopes suburban women, turned off by Trump's bombastic rhetoric, could be a key source of support for her in the fall.

But she's also trying to stop Sanders from gaining the psychological advantage of a series of wins this month. Her team went up with a $160,000 ad buy in Kentucky on Tuesday, a modest effort aimed at cutting into Sanders' support before the state's primary in a week.

Billionaire businessman Trump said in a statement after Tuesday's elections that he plans to return to both states soon, and win them in the general election this November.

Trump says, "I learned a lot, and that knowledge will be put to good use towards the creation of businesses, jobs and the strengthening and revival of their economies."

In Nebraska's Republican primary, the overwhelmingly majority say their party is divided and a significant portion of them don't see that as changing by November.

Those are among the findings from exit polls conducted for The Associated Press and television networks by Edison Research.

Ted Cruz, who suspended his bid for the Republican presidential nomination last week, had earlier hinted he may rejoin the race if he won in Nebraska.