Supporters of Sen. Bernie Sanders hold up a sign on the second day of the Democratic National Convention at the Wells Fargo Center, July 26, 2016 in Philadelphia, Pennsylvania. (Photo: NICHOLAS KAMM/AFP/Getty Images)

PHILADELPHIA (CBSNewYork/AP) — Bernie Sanders loyalists believe the Democratic Party could rupture over Hillary Clinton’s nomination after a volatile night that saw Sanders delegates leave the party’s national convention in Philadelphia to stage a sit-in at a media tent.

Protesters are rejecting Sanders’ call for unity, even after the Vermont senator declared Clinton the winner of the delegate count at Tuesday’s convention.

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A large group of Sanders delegates and supporters exited the Philadelphia convention site shortly after Clinton’s nomincation to hold a sit-in inside a media tent.

Some had their mouths taped shut. A few spontaneously sang the chorus of the folk song “This Land is Your Land” and a banner read “We The People.”

They said they were holding a peaceful protest to complain about being shut out by the Democratic Party.

DEVELOPING: Sanders protestors gathering outside the convention center after walk out. pic.twitter.com/RhPfkNHxsd — CBS Evening News (@CBSEveningNews) July 27, 2016

“This was not a convention. This was a four-day Hillary party and we weren’t welcome,” said Liz Maratea, a New Jersey delegate at the media tent protest. “We were treated like lepers.”

Thousands of activists have also taken to the streets during the convention this week to support Sanders and his progressive agenda. On Tuesday, protesters began scaling 8-foot walls blocking off the secure zone around the arena parking lot.

College student Cory James of Flint, Michigan, said he expects the Democratic Party to split over the nomination.

“I suspect we are witnessing an event that will fundamentally change American politics,” he said.

Another Sanders supporter, Nomiki Konst, told CBSN what it would take to turn things around.

“She’s got to earn these people’s votes,” said Konst, who called on Clinton and her campaign to meet with some of the delegations “and listen to their concerns.”

She said at the moment, Clinton’s campaign feels “a little bit tone-deaf” as if “there’s something missing.”

But their critics fear they may inadvertently help Republican nominee Donald Trump. Tiara Willis, of Philadelphia, subscribes to the slogan, “I’m with her — I guess.” She called Clinton, “the lesser of two evils.”

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)