PHILADELPHIA — It's over for Bernie Sanders. But not for them, the fresh-faced army that packed a downtown square Tuesday afternoon, punching fists in the air to cries of "Bernie or bust."

The rally — hours before Hillary Clinton officially captured the Democratic presidential nomination — illustrated the passion that drove 74-year-old Sanders' remarkable run.

It also shows a glaring weakness of Clinton: young voters.

"I don't trust her. She's been involved in a lot of scandals. She flip flops. She'll try to pander to Latinos, women," said Andrea Manrique, 26, who could not think of a single friend back home in California supporting Clinton.

"I just don't like her," said Alyssa Behrendt, 19, of Iowa.

Protest organizers called on the group to use social media to foment a Never Hillary movement. One speaker lashed out at comedian Sarah Silverman, a Sanders supporter who rebuked the hold-outs during a convention speech Monday night. "You're being ridiculous," Silverman had said.

It's plain to see why some Democrats dismiss such recalcitrance, repeated Tuesday when hundreds of delegates, of all ages, walked out after Clinton clinched the nomination. They are Sanders' truest believers. But party leaders are confident that young voters, given the choice, will come around by November.

"When the hard reality sets in, when it's Hillary versus Donald, that's going to wipe away any of the concerns some of the Sanders people have," said Sen. Bill Nelson of Florida, who attributed Clinton's negative approval rating to decades in the public arena.

Yet interviews with Sanders' backers revealed many are looking to a third party candidate, often naming the Green Party's Jill Stein, who is in Philadelphia to court voters. This should concern Clinton, who saw Sanders dominate her among young voters in the primaries.

Sanders got more votes from people age 18-29 than Clinton and Trump — combined — more than 2 million to their nearly 1.6 million, according to an exit poll analysis by researchers at Tufts University.

In New York, Clinton's home state, Sanders beat her among the group by 30 percentage points.

In Florida, where Clinton also won easily, Sanders' advantage was 35 points.

"Bernie Sanders appears like a grandfather to young voters. The sort of grandfather that would say the truth to you. If you are failing in school, you should study more," said Miguel Valdez, 32, of Gainesville. "Young people are craving integrity, honestly, straightforwardness and that's why he connects so well."

Valdez, incensed by leaked party emails showing bias against Sanders, said he will support the nominee but thinks Clinton will lose. "The Democratic Party is giving the nomination to the weaker of the two candidates. We're going to have President Trump," he said, punctuating the line with an expletive.

Carlos Turcios, 26, said he planned to vote for Clinton after she moved to the left on trade and college funding. But then came the email scandal, which reinforced hard feelings about the establishment and an overall perception that Clinton is untrustworthy. "I'm against Trump, but Hillary's in the same boat. I don't like her dishonesty."

President Barack Obama's historic 2008 victory was driven by young voters like Turcios. But the Las Vegas resident said he was disappointed Obama did not push harder on climate change and immigration. In Sanders he saw an authentic figure and a fighter, the candidate who believed in universal health care and eschewed super PACs.

"I didn't know a movement can become so big where you can feel so inspired and you feel there might be some change," Turcios said Sunday night while meeting friends in a downtown bar.

In bars, restaurants and at the convention hall here, young Sanders supporters are much more visible than Clinton ones. It was a scene repeated on the campaign trail, Sanders' rallies crammed full of college students who viewed him as revolutionary. Sanders is a self-styled "democratic socialist," and surveys have shown younger voters have a less negative perception of socialism.

As Sanders dominated the demographic, Clinton showed signs of frustration, telling Politico, "There is a persistent, organized effort to misrepresent my record, and I don't appreciate that, and I feel sorry for a lot of the young people who are fed this list of misrepresentations."

Leading Democrats cringed.

In another interview, Clinton said she was not "worried about how he has attracted so many young people because I think that it is important to bring them into the process, and I give him a lot of credit for doing that.

"My argument basically is, look, we are electing a president and a commander-in-chief. We are electing the Democratic Party standard bearer to go up against whoever the Republicans wind up nominating and we really need to be sure that we elect someone who can walk into that Oval Office on January 20, 2017, and start making decisions about people's lives and livelihoods. And when folks look at that, I feel very confident both in the nominating process and in the general election."

Trump has worked to court Sanders voters, but interviews in Philadelphia backed up the idea the millennials will not go for him. A Rock the Vote poll in April showed Clinton winning the millennial vote 52 percent to Trump's 19 percent. Republican presidential candidates have not won the youth vote since 1988.

Still, Clinton is working to shore up her weakness, bringing on some of Sanders' staff and mining the voter data he used to reach voters. "Unity events" are being held in Florida and other states that feature supporters of both candidates. Digital advertising has been created expressly to reach younger audiences.

Earlier this month, Clinton embraced Sanders' call to tackle the cost of higher education, outlining a plan that would provide free tuition for public colleges and universities for students with family incomes of $85,000 or less, a threshold that would grow to $125,000 by 2021.

Clinton has also promised an executive action placing a three-month moratorium on college loan repayments from federal borrowers so borrowers can explore cost-saving measures.

Ana Cruz, former executive director of the Florida Democratic Party and a Clinton delegate, said Sanders has to keep doing his part, "to not just encourage but almost be evangelical with his supporters to come out and embrace the platform changes and embrace this ticket. Hillary Clinton did it in 2008."

"It's up to him," Cruz said. "He created this and he really needs to encourage his supporters to back the Clinton-Kaine ticket."

Kent Willis, 28, of Gainesville said he views Clinton as "more of the same," uninspiring and a "defeatist" on her health care vision of the 1990s. But with Clinton now the nominee, he said, "Not voting is useless."

He won't commit to her yet. "There's a lot of time between now and November, so we want to see how Hillary progresses."

Contact Alex Leary at aleary@tampabay.com. Follow @learyreports.