CHARLESTON, S.C. -- House Majority Whip James Clyburn endorsed Joe Biden on Wednesday for the Democratic nomination for president, giving a boost to the former vice president, who is banking on the strong support of black voters to propel him to victory in South Carolina's primary this weekend.

Clyburn, a prominent South Carolina Democratic legislator and leader in the African-American community, made the announcement during a press conference Wednesday morning, touting Biden’s record and their relationship.

BIDEN CAMPAIGN VOWS VICTORY IN SOUTH CAROLINA, SAYS RACE IS 'JUST GETTING STARTED'

“I’m voting for Joe Biden. South Carolinians should be voting for Joe Biden,” Clyburn said. “I know who he is, I know what he is. I know where this country is. We are at an inflection point.”

He added: “I know Joe. We know Joe. But most importantly, Joe knows us.”

Clyburn went on to say that he can “think of no one more prepared, no one with the integrity, no one more committed to the fundamental principles that make this country what it is.”

“In South Carolina, we choose presidents,” Clyburn tweeted Wednesday morning. “I’m calling on you to stand with @JoeBiden.”

The endorsement comes just days before a critical race for the Biden campaign, who has long called South Carolina his firewall.

The Biden campaign, before Tuesday night’s Democratic debate, vowed victory in Saturday’s South Carolina primary, saying they have no concerns over whether or not they will win.

SANDERS ONCE COMPLAINED ABOUT EARLY SOUTHERN PRIMARY, SAID CALENDAR 'DISTORTS REALITY'

“We fully intend to win South Carolina,” Biden campaign senior adviser Symone Sanders said Tuesday. “We feel great about our ground game -- we have good ground game here. We’ve spent a lot of time in the state, we’ve invested a lot of resources in the state, and we think we will do extremely well.”

She added: “We’re not concerned about losing South Carolina because it’s not going to happen.”

Some supporters, though, are downplaying the importance of winning the state. Rep. Cedrick Richmond, D-La., who is a strong supporter and surrogate of Biden, told reporters after the debate Tuesday night that South Carolina didn’t have to be a firewall, but was instead a “launching pad” to bring the campaign into Super Tuesday.

According to the latest RealClearPolitics average for the South Carolina primary, Biden is leading the field with 30.3 percent of the vote. Sen. Bernie Sanders, I-Vt., the virtual front-runner, is trailing the former vice president with 22.3 percent of the vote.