Vermont Sen. Bernie Sanders urged his supporters to keep up the fight Monday, despite near-impossible odds against him winning the Democratic presidential nomination from front-runner Hillary Clinton.

The self-described democratic socialist's last-ditch drive begins with Tuesday's primary in West Virginia, where polls have shown Sanders leading Clinton.

Although her delegate lead nationally is almost insurmountable, Clinton has faced backlash in Appalachia for saying on television in March that she would "put a lot of coal miners and coal companies out of business." She was responding to a question about how her policies would benefit poor white people in Southern states.

While trying to make peace with the coal community in Williamson earlier this month, she was met with protests. Responding to an unemployed coal worker, she said she made a "misstatement." Clinton released a $30 billion plan last fall aimed at aiding communities dependent on coal production.

Despite a drop in fundraising that has forced his campaign to cut back on staffers and advertising, Sanders continues to draw enthusiastic crows to his rallies. On Monday, Atlantic City, N.J. heard his never-say-die message. 

"If we can win here in New Jersey and win in California [June 7] and win in some of the other states and if we can win a majority of the pledged delegates, we're going to go into Philadelphia and the Democratic convention and expect to come out with the Democratic nomination," Sanders said.

While Clinton hasn't called on Sanders to exit the race, his insistence that a path exists is frustrating to her supporters and campaign aides. The White House has said it won't get publicly involved until Sanders formally ends his bid, keeping three of the party's most powerful spokespeople — Obama, first lady Michelle Obama and Vice President Joe Biden — largely on the bench.

On the Republican side, presumptive nominee Donald Trump is expected to win West Virginia handily.  At a rally last week in Charleston, the real estate mogul reminded supporters that he doesn't need the win anymore.

"Now what I want you to do is save your vote. You know, you don't have to vote anymore," Trump said. "Save your vote for the general election, OK? Forget this one. The primary's gone. Save your vote for the general election in November. And we're going to show you something, and you're going to show me something."

Republicans in Nebraska will also make their presidential pick Tuesday, but turnout could be smaller than expected with Trump the lone candidate left in the Republican race.

The Associated Press contributed to this report.