Philadelphia, USA - On Tuesday night, just as soon as the roll call vote ended and Vermont Senator Bernie Sanders endorsed Hillary Clinton for the Democratic Party's nomination, his supporters walked out of the convention and staged a sit-in at the media tent, where I and hundreds of other journalists were filing stories.

His hardcore disciples could not fathom how, after months of supporting the socialist senator and his message, he could ask them to support Clinton.

They held up signs calling for a revolution and chanted, "This is what democracy looks like".

With policemen standing behind them silently in formation, two women who had black cloths over their mouths to symbolise their lack of voice at the Democratic National Convention (DNC) held a sign saying, "No justice, no peace".

READ MORE: Leaked emails appear to show DNC hostility to Sanders

I spoke with Rashane Handy, 25, a single mother from Kansas. Visibly shaken, and sitting on the floor with other supporters, she said she was tired of being misrepresented.

"We need progressives on the ballot. Our healthcare is suffering and our education is suffering. Sanders didn't just bring out political people; he brought out people like me, single moms, black people, Latinos. If we vote for Hillary, we'd be voting for the lesser of two evils," said Handy.

In the past few days, while covering the protests being held on the sidelines of the DNC, I spoke to many Sanders followers.

Young and old, men and women, most called Clinton a warmonger. A common theme among them was their belief that she had close ties with Wall Street - an issue they felt strongly about.

All but one said they felt they were being made to choose between the lesser of two evils; that Donald Trump, the Republican nominee, was essentially a "boogeyman" they were being threatened with in order to cast their ballot for Clinton.

Many were instead thinking of voting for Jill Stein, the Green Party's presumptive nominee. Along with "Jill, Not Hill", "DemExit", [a play on Brexit] was another common slogan at rallies, held up by people threatening to leave the party, in the hope that Sanders would run as an independent.

Two girls I spoke with said they were ashamed of Clinton. Their reasons included her role in Benghazi, her endorsement of the Trans-Pacific Partnership [one of President Barack Obama's big trade deals], and for "paying women in her office less than men during her time in the US Senate".

They also criticised the DNC for "denying independents the right to vote for their president, voter suppression and fraud, and for conspiring against Bernie Sanders".

Many held signs that read, "I'm not with her", and "Bernie, Never Hillary".

Chelsea Sarnecki, a young woman from Indiana, told me she felt that Clinton had political and corporate ties that would not be in the best interests of the country.

When asked whether Trump was a better alternative, she didn't really have an answer. Replying to that same question, others said it would not be their fault - but rather the rigged system's - if Trump were to win in November.

Sanders' followers are having a hard time believing that he has lost - fair and square.

The recent leaked cache of emails, showing the DNC chairwoman's bias against the Vermont senator, has supported their theory that the party conspired against the Jewish socialist in favour of the establishment candidate.

His disciples know that people think they're spoilers, who will usher in a Trump presidency. But to them, this is bigger than Sanders himself. They booed him the last time he told them to support Clinton and her vice presidential candidate Tim Kaine.

To them, this is about everything he promised would be part of America should he become president: better healthcare and education, more jobs, and a fairer justice system.