BALTIMORE -- Bailey Myers, a 20-year-old Bernie Sanders supporter attending a boisterous rally here Saturday, said even if Sanders doesn't win the Democratic nomination, the campaign has shown him that the party is approaching the same kind of crackup between its ideological base and establishment that has afflicted the GOP for years now.

"(Sanders) is in charge of that movement right now, and it will continue with or without the Democratic Party," said Myers, a Loyola University student.

Sanders' supporters, perhaps for the first time in this tumultuous presidential race, are reflecting on the campaign, the highs and lows of a long primary and what it all has meant for the progressive movement.

Sanders' decisive defeat in the New York primary last week snapped his winning streak against Hillary Clinton and might have ended his already faint hopes of closing a prodigious delegate deficit -- especially if, as expected, he is dealt another series of losses during Tuesday's primaries.

Sanders supporters' devotion -- evident at the rally, prompting the kind of screaming and yelling heard at rock concerts -- has fueled a remarkably successful insurgent campaign, one that has rung up big and unexpected victories despite almost no institutional support within the Democratic Party.

Now, though, even many of these diehards admit things are different.

You wouldn't think Richard Stafford and Patricia O'Brien were Hillary Clinton donors if you saw them at the rally wearing matching Bernie T-shirts. But this white 60-something husband and wife from nearby Clarksville, Md., hadn't seen Sanders speak when they contributed $100 to the Democratic front-runner's campaign in June.

"The first time we heard Bernie, we said, 'OK, he's the man. He's the one,'" said O'Brien, who like her husband is retired.

It was a common refrain among the thousands of Sanders fanatics at the Saturday rally at a small downtown arena: They didn't know much about the senator from Vermont when he started his presidential campaign, but it didn't take long to learn to love him.

"It's been a rollercoaster, no doubt about it," said John Murphy, 76, who attended the event with his wife and daughter.

Those impressions are equal parts hopeful and alarming for Clinton and the rest of her party. Sanders supporters are, almost to a person, true believers in the cause. In interviews, they offered a litany of reasons why they back the candidate: his stance on climate change, his openness to the Palestinian people, and his fight for income inequality.

But ultimately, their support sprung out of the belief that Sanders has the courage and honesty to give the country a necessary clean break from a status quo they no longer see as tenable.

The emotional investment in Sanders shouldn't be a surprise. His supporters have lived and died with his campaign since the Iowa caucuses, treating election nights spent watching the news like a major sporting event. Joe DiNato, 33, from Baltimore County, said he and two friends drove to Iowa together to volunteer for the campaign before the Feb. 1 showdown.

Watching on TV that night, he added, brought a lot of yelling as the vote share for Sanders and Clinton went up and down.

"You would have thought we were watching the NBA Finals," he said. "You get emotionally invested for sure."

If they were emotional, it was in part because many of them never expected Sanders would be this competitive. Even ardent supporters said that, at first, they didn't expect much from his campaign.

"When I first heard he was running, I thought, that's ridiculous," said Liz Zogby, 43, a resident of Baltimore. "That's a waste of everyone's time. I had no inkling at all that he could win."

But as Zogby, daughter of longtime Arab-American Institute President James Zogby, and other Sanders supporters explained, that his early wins _ especially his unexpected triumph in Michigan in early March _ gave hope that he might actually defeat Clinton.

She's less convinced Sanders can win, calling last week's defeat in New York a "bummer." At the rally, however, there were few signs that Sanders or his supporters were ready to let go of the campaign.

"What this campaign is about is having the courage to address issues the establishment would rather sweep under the rug," said Sanders, who gave a more than hour-long-version of his stump speech that had his supporters cheering uproariously.

The question now hovering over Sanders' campaign is whether he, facing a close-to-insurmountable deficit in delegates, will ease up on his criticism of Clinton and perhaps even drop out of the race before the convention in Philadelphia.

He continued his criticism of the former secretary of state during his speech, accusing her of using Wall Street-funded super PACs and supporting an insufficient hike in the minimum wage.

Many of his supporters said they knew that Sanders' hopes of winning the nomination were a long shot, but they still held hope he could mount a late comeback. Nearly all were supportive of him continuing his campaign through the last primary in California, in June.

If Clinton does win the nomination, she'll have some work to do to convince Bernie backers that she deserves their support. At the rally, many of them confessed they weren't eager to support her in a general election.

"I have no faith that the Democratic establishment is going to notice the fact there's a movement afoot that would actually help the Democrats be the party of the people by growing its members base by embracing what's in front of them," said Sue Fothergill, 43, of Baltimore.

Stafford and O'Brien said they have atoned for their $100 contribution to Clinton by sending Sanders $10 a month every month – in addition to chipping in with extra cash when his campaign asks for it. They retain hope that Sanders will win, struggling to grapple with the notion that a candidate who resonates with them like never before could go down in defeat.

"What he says I've been yelling at my friends for 20 years," said Stafford.

But even if he does, Stafford added, all is not lost.

"I hope he wins, but he already has won," he said. "He got his message out."