"You in fact are likely to determine who the next President will be," Biden said. "And it all starts in South Carolina."
Biden spent no time on his Democratic colleagues, instead focusing all of his ire on President Donald Trump.
"This President has done more to destroy the essence of who we are as a nation than any President in history," Biden said.
Biden did not have Charleston to himself, as candidates were either speaking to the state party dinner, or holding their own rallies across town.
"Hello Charleston!" Elizabeth Warren said at her own rally, as the Massachusetts Democrat stuck with the roots of her stump speech, and focused on her many plans for 'structural change.'
"It is time for a wealth tax in America," Warren said to cheers, as she told the crowd to remember, "the first $50 million is 'free and clear.'"
Wrapping up her speech, Warren almost seemed to plead with her audience to drum up support for her on Saturday, as she tries to find a way forward through Super Tuesday.
"This is our moment," Warren said. "Vote for me - but more - get in this fight."
On Sunday in Arlington, Virginia, Pete Buttigieg drew 7,000 people to an outdoor football stadium, with hundreds more forced to listen from outside the gates.
But it was a much smaller audience which greeted the Indiana mayor at an event in North Charleston on Monday evening, as Buttigieg made his pitch for votes in Saturday's primary.
Polls have consistently shown Buttigieg struggling to break into double digits in the Palmetto State - as the Buttigieg schedule also has him traveling to other states this week, with Super Tuesday looming on March 3.
While last week's debate saw the knives get sharpened for former New York Mayor Michael Bloomberg, it could be Sanders who is in for the biggest challenge on Tuesday night.
"I am absolutely confident that no matter who wins, we are going to unite," Sanders said.
"Donald Trump is a one term President," the independent Senator from Vermont added.