06/06/2016 00:00 EDT | Updated 06/06/2017 01:12 EDT

Back Clinton or not? On brink of possible defeat, Sanders fans face big dilemma

SAN FRANCISCO — A soul-searching exercise awaits Democrats opposed to Hillary Clinton, who is on the cusp of securing their party's presidential nomination Tuesday.

They'll soon be asked to support her in the general-election showdown against Donald Trump if she concludes the last big batch of primaries with an insurmountable lead, as expected.

But talk to Bernie Sanders supporters, and many sound ambivalent. As his social-democratic Cinderella story approaches its political midnight, the senator's fans seem torn.

Most tell pollsters they'd rally behind Clinton; one-quarter say they wouldn't; yet in interviews, many reveal they're grappling with a quandary.

Greg Elsten is an artist and he uses graphic images to illustrate his dilemma. In cringe-inducing corporal terms, he describes his feelings about being forced to choose between Clinton and Trump.

"It's either a slap in the face or the kick in the crotch," he says. The silver lining here for Clinton? Elsten views her as the lesser of the two agonies: "She would be the slap in the face."

If absolutely forced to, he says he'd be willing to endure the facial sting of voting for someone he finds as cynical and shifty as Clinton. Maybe if he lived in a swing state like Ohio, and believed his vote necessary to shield America from a kick in the unmentionables in the form of President Donald Trump.

But he lives in solidly Democratic California. So he figures he can afford to write Sanders' name into the ballot in protest — like he's decorated the Uber car he drives with a Sanders sticker and button, and filled the back seat with pamphlets for passengers to read during their rides.

Sanders' own improbable ride could be ending.

The senator is eight per cent behind in elected delegates, he's even farther behind among so-called superdelegates of party officials and, barring a shocker Tuesday when six states vote including California and New Jersey, he'll be essentially eliminated.

Sanders has already indicated he plans to keep fighting.

Clinton will still need some superdelegate votes at the convention, unless she outperforms expectations Tuesday. The Vermont senator suggests he might seek to convince those party officials to back him at next month's convention — even though Clinton's won more votes, more states, and more delegates.

Sanders supporters say something else might change between now and the July convention. Something like criminal charges being laid against their opponent. 

The FBI is still investigating Clinton's use of a home email server for work. Some are apparently holding out for police intervention: "We're yet to hear the last of that, I hope," said Kate Tanaka at a Sanders rally last week in Oakland.

Tanaka hasn't voted Democrat in a quarter-century, not since Bill Clinton. She's more recently supported either Ralph Nader or the Green party. Like actress-activist Susan Sarandon, she's in the so-called "Bernie-Or-Bust" camp.

She wouldn't vote for Clinton.

"Never, never," Tanaka said. "I will go back to what I was doing before Bernie came along. I'd vote for (the Green party)... I don't want Donald Trump, but I don't want Hillary Clinton. I think she poses some really serious threats (too)," she said, referring to her hawkish military positions.

Others sound ready to hop aboard the Clinton bandwagon.

"As much as she's not the person in the primary that I voted for, I have no problem voting for her as the party candidate," said Timothy Egan of New Hampshire.

"I think a lot of (Sanders fans) will support her. Because the alternative is don't vote, or vote for Donald Trump. And I think they're too passionate to not vote, and they're too intelligent to vote for Donald Trump."

He predicted Sanders would ultimately back her too, because that's the best way to retain some political influence and keep pushing the causes he cares about.

At a Sanders rally in California, Yelda Bartlett was unequivocal when asked whether she'd be able to switch to Clinton: "Definitely," she said. 

"I'm an immigrant. I'm Muslim. My family's Muslim. I can't vote for a demagogue (like Trump). It's scary to me."

Others, like Elsten, fall somewhere in the middle.

People in this category tend to lay out conditions for their support — Elsten's relates to geography, and whether his vote would make a difference in a swing state.

Jeanne Andrews says she'd want other "concessions" from Clinton. As she waited six hours to get into a Sanders rally last week, Andrews said she'd expect some of Sanders' policies in the platform. 

One particular move would win her over immediately: "Bernie for vice-president. (Then) I'm in. I'm all in... It's not just about putting that man in that office. It's what he stands for."

Another person in line also raised the Sanders-as-running-mate idea.

"I think the only way I could vote for her is if Bernie was the vice-president," Terry Baxter said.

America Votes
The latest polls, breaking news and analysis on the U.S. election from HuffPost’s Washington, D.C. bureau