Hillary Clinton has wiped away bitter memories of her loss to Barack Obama in South Carolina eight years ago, cruising to a predictable but commanding victory over Bernie Sanders in the 2016 US presidential primary and drawing overwhelming support from black Democrats.
Mrs Clinton's win gave the former US secretary of state's White House campaign a huge boost and puts her in a strong position as the race heads towards crucial multi-state contests on Tuesday.
"To South Carolina, to the volunteers at the heart of our campaign, to the supporters who power it: thank you," she said on Twitter. At a campaign victory party in Columbia, supporters broke into raucous cheers as the race was called in her favour.
She told her victory rally that "tomorrow this campaign goes national" as she and Mr Sanders compete for the Super Tuesday states.
To cheers, she said: "When we stand together there is no barrier too big to break."
Mr Sanders, expecting defeat on Saturday, left the state even before voting was finished and turned his attention to some of the states that vote in this week's Super Tuesday delegate-rich contests.
He vowed to fight on aggressively, saying: "This campaign is just beginning. Our grass-roots political revolution is growing state by state and we won't stop now."
Black voters powered Mrs Clinton to victory in South Carolina, with eight in 10 voting for her. She also won over most women and voters 30 and older, according to early exit polls.
Her victory came at the end of a day that saw Republican candidates firing insults at each other at rallies in states voting on March 1.
Donald Trump, working to build an insurmountable lead, was campaigning in Arkansas with former rival New Jersey governor Chris Christie and calling Florida senator Marco Rubio a "light little nothing".
Texas senator Ted Cruz asked parents in Atlanta, Georgia, if they would be pleased if their children spouted profanities like brash billionaire Mr Trump. And Mr Rubio mocked Mr Trump as a "con artist" with "the worst spray tan in America."
Mrs Clinton made a stop in Alabama, a Super Tuesday state, on Saturday, before returning to Columbia, South Carolina's capital, for an evening victory party.
Mr Sanders drew 10,000 people to a rally in Austin, a liberal bastion in conservative Texas, the biggest Super Tuesday prize.
He has energised young people and liberals with his impassioned calls for breaking up Wall Street banks and making tuition free at public colleges and universities. But the senator from Vermont, a state where about 1% of the population is black, lacks Mrs Clinton's deep ties to the African-American community.
Mrs Clinton's sweeping victory suggested South Carolina voters had put aside any lingering tensions from her heated 2008 contest with Mr Obama. Her husband, former president Bill Clinton, made statements during that campaign that were seen by some as questioning the legitimacy of the black presidential contender.
This time around though, Mr Clinton was well-received as he travelled the state on his wife's behalf. She focused on issues with particular resonance in the black community, including gun violence, and held an emotional event with black mothers whose children died in shootings.
Mrs Clinton's second White House bid lurched to an uneven start, with a narrow victory over Mr Sanders in Iowa and a crushing loss to the senator in New Hampshire. She pulled off a five-point win over Mr Sanders in last week's Nevada caucuses, a crucial victory that helped stem his momentum.
Her campaign now hopes her strong showing in South Carolina foreshadows similar outcomes in states like Georgia, Alabama, Tennessee and Virginia that vote on Tuesday and have large minority populations.
Taken together, 865 Democratic delegates are up for grabs in the Super Tuesday contests in 11 states and American Samoa.
Because Democrats assign delegates proportionally, Mr Sanders is simply hoping to stay close to Mrs Clinton in the South, but he is focusing most of his attention on states in the Midwest and Northeast, including Vermont.
On the Republican side, voters will cast ballots in 11 states, with 595 delegates at stake on Super Tuesday.