Earlier in the evening, multiple attendees complained about media outlets calling the race for Mrs. Clinton before all of the precincts reported their results. “I don’t know why people in South Carolina give up so fast,” a campaign volunteer who had traveled from California said. The volunteer, a white man, noted that only the “old black vote” from rural counties had come in at that point, adding, “Who cares?” (He quickly appended, “I don’t want to sound racist or anything...”)

Women at the watch party were the most openly angry about the results. As Mrs. Clinton delivered her victory speech, a middle-aged woman jokingly plugged her ears and said “La la la!” Another sarcastically sang “All You Need Is Love” — a dig at Mrs. Clinton’s repetition of the phrase “love and kindness” — and added, “She’s playing to the hippie crowd!” A younger woman took a more direct route and emphatically gestured at the screen with a symbol meant to indicate the opposite of love and kindness.

After Mrs. Clinton finished her speech, Symone Sanders, a spokeswoman for the Sanders campaign, stood up in front of the screen at Pearlz.

“Today is not the end. Today is the beginning,” she said, to cheers.

As 9 p.m. came and went, the Sanders’s crowd’s insistence on having a good time took on an air of civil disobedience. Justin Bamberg, a state representative — who notably switched his support from Mrs. Clinton to Mr. Sanders — took the stage to thank the attendees.

“Keep your head up, because we are not done yet,” Mr. Bamberg said. “Crank the music up!”

Over the past week, as Mrs. Clinton and an army of surrogates barnstormed South Carolina, Mr. Sanders made sporadic visits to the state. He has already turned his attention toward Super Tuesday contests, holding rallies in Missouri, Oklahoma, Ohio, Michigan, Illinois, Texas and Minnesota, along with South Carolina. A rally at a raceway in Austin on Saturday drew more than 10,000 people, according to his campaign.

As the South Carolina primary neared, Mr. Sanders started openly managing expectations for this contest. At Claflin University in Orangeburg, S.C., on Friday, Mr. Sanders admitted that he and his campaign didn’t know many people from South Carolina before he started running for president, but said he was proud of the ground he had gained.

At the same event, the rapper Killer Mike sharply criticized Mrs. Clinton for how she dealt with a protester at a fund-raiser on Thursday night. He compared Mrs. Clinton’s behavior to Mr. Sanders’s reaction when two young women representing the Black Lives Matter movement interrupted one of his campaign events last year.