In most presidential primary campaigns, the battling ends at some point, and the frontrunner just runs up the majority. And the winning candidate gets stronger and stronger as the primary season ends. Look at Donald Trump. He started off as a joke, became a phenomenon, there was serious talk about a contested convention, even running a Republican as a third-party candidate, and now one after another former foe is endorsing the billionaire.

Not so on the Democratic side. Hillary Clinton was the “presumed nominee” before the race began. Her lightweight opponents didn’t last long, and Bernie Sanders was a joke—before he became a phenomenon. Now, he clearly has the excitement and the momentum, even though he’s over three million popular votes behind, and if she can hang onto her Superdelegates, Hillary should be way over the mark after Tuesday.

But there are still those who say Bernie could beat her. This from the Independent:

US election 2016: Hillary Clinton could lose Democratic nomination to Bernie Sanders

A big win in the 7 June California primary could hand Mr Sanders hundreds more delegates, which would call into question Ms Clinton’s candidacy. . .

Mr Sanders will be looking to the state to boost his campaign with news of a further 1.5 million people registering to vote since January this year.

The latest statistics from the Institute of California will be encouraging to Mr Sanders as a big win in the 7 June California primary, where the candidates are currently virtually deadlocked, could hand him hundreds more delegates. Mr Sanders currently has 1,501 pledged delegates to Ms Clinton’s 1,769.

Up to now, Bernie has been seen as just an impediment for Hillary. There has not been serious talk of Bernie actually getting the nomination. But now, there is increasing talk that a loss in California—where she won in 2008—could undermine Hillary’s status as a winner against Donald Trump.

And a former Bill Clinton polster says Hillary really could lose California, according to Townhall.

Hillary’s campaign is doing all it can in the remaining days to avoid an embarrassing loss in the Golden State, jamming 30 events into the few days leading up to the primary.

“If she loses California, which is now increasingly likely,” Douglas Schoen, former pollster and political adviser to Bill Clinton, said on Fox News. “She’s behind Donald Trump in a number of polls, we’ve got the Justice Department likely to render a judgment that finds some culpability somewhere, don’t you think … that the Democratic Party will say ‘Why do we need this? Why do we need to risk a defeat with Secretary Clinton?’”

Schoen expanded on the theme in the Wall Street Jourmal.

A Sanders win in California would powerfully underscore Mrs. Clinton’s weakness as a candidate in the general election. Democratic superdelegates—chosen by the party establishment and overwhelmingly backing Mrs. Clinton, 543-44—would seriously question whether they should continue to stand behind her candidacy.

There is every reason to believe that at the convention Mr. Sanders will offer a rules change requiring superdelegates to vote for the candidate who won their state’s primary or caucus. A vote on that proposed change would almost certainly occur—and it would function as a referendum on the Clinton candidacy. If Mr. Sanders wins California, Montana and North Dakota on Tuesday and stays competitive in New Jersey, he could well be within 200 pledged delegates of Mrs. Clinton, making a vote in favor of the rules change on superdelegates more likely.

Another problem: In recent weeks the perception that Mrs. Clinton would be the strongest candidate against Donald Trump has evaporated. The Real Clear Politics polling average has Mrs. Clinton in a statistical tie with Mr. Trump, and recent surveys from ABC News/Washington Post and Fox News show her two and three points behind him, respectively.

Then there is that other crack in the argument for Mrs. Clinton’s inevitability: Bernie Sanders consistently runs stronger than she does against Mr. Trump nationally, beating him by about 10 points in a number of recent surveys.

The rumblings on the Democratic side are getting louder. If Bernie is not the nominee, Hillary may not be able to count on many of his supporters. Many highly educated Democrats have decided they cannot support Hillary.

And they don’t come by these views casually. Their conclusions are the result of careful study of her record and her policy proposals. They believe the country can no longer endure the status quo that Clinton represents—one of crushing inequality, and an economy that is literally killing off the less fortunate—and any change will be better. One reader writes:

“If Clinton is the nominee 9 out of 10 friends I polled will [do one of three things]:
A. Not vote for president in November.
B. Vote for Trump.
C. Write in Bernie as a protest vote. . .

As another reader puts it:

“I don’t want to vote for Trump. I want to vote for Bernie. But I have reached the point where I feel like voting for Trump against Clinton would be doing my patriotic duty. … If the only way to escape a trap is to gnaw off my leg, I’d like to think I’d have the guts to do it.”

. . . Some of them also have very reasoned arguments for Trump. Hillary is a known evil. Trump is unknown. They’d rather bet on the unknown, since it will also send a big message to Team Dem that they can no longer abuse progressives.

In “the year of the outsider,” even Democratic Party stalwarts are beginning to question whether the establishment candidate is a wise choice. The talk about Hillary’s inevitability is long gone. The chuckles about a contested convention have subsided. For the first time, there is serious talk of Bernie Sanders actually becoming the Democratic Party candidate for president in 2016.