Not even five days ago, former Vice President Joe Biden's bid for the 2020 Democratic nomination seemed as if it had hit a snag following a string of disappointing performances throughout February.

But then there was the South Carolina primary -- the beginning of Biden's bounceback.

Propelled by the coveted endorsement of the Palmetto State's Jim Clyburn -- a kingmaker and the highest-ranking black American in Congress -- as well as by the state's majority-black Democratic electorate, Biden trounced Sanders by nearly 30 points.

Clyburn reacted to Biden's super Super Tuesday by reiterating his endorsement and the importance of Democrats rallying around the former vice president.

"I feel that this country's democracy is at stake. I've said time and time again, no matter what we may do to provide health care, affordable housing, educational opportunities, economic opportunities, none of that matters if we do not have a stable, flourishing democracy. And that's what I was trying to do, because I do believe in Joe Biden," Clyburn said of his endorsement

On Super Tuesday, Biden saw a sweep across the South Black voters made up about a quarter of the electorate in North Carolina, Virginia and Tennessee, more than 4-in-10 voters in Alabama, and 2-in-10 in Texas -- all states the former vice president won. (Biden also grabbed victories in Arkansas, Oklahoma, Minnesota and Massachusetts.)

Another way to look at all this: In the span of just 72 hours, between the South Carolina primary on Saturday and Super Tuesday, black voters in the South shaped the Democratic race in a manner that the Iowa and New Hampshire contests didn't -- couldn't.

That's due at least in part to demographics. Iowa and New Hampshire are overwhelmingly white -- about 90% -- which doesn't reflect a Democratic Party base that's some 40% nonwhite . In consequence, two unrepresentative states receive lots of attention as the general election approaches in earnest, and voters there prop up candidates who appeal mostly to them.

This narrative-setting is at odds with the fact that, without the backing of voters of color -- particularly black voters -- a candidate has almost no path in the Democratic Party. (Ask former South Bend, Indiana, Mayor Pete Buttigieg , who suspended his campaign on Sunday.)

Ahead of Super Tuesday, where about one-third of pledged delegates were at stake, Biden nodded to the value of securing black voters' support.

"I've worked like the devil to earn the vote of the African American community. Not just here, but across the country. I've been coming here for years and years, creating jobs here," he said during the Democratic primary debate in Charleston, South Carolina, in February. "The people know me. My entire career has been wrapped up in dealing with civil rights and civil liberties."

Crucially, this doesn't mean that black voters are a monolith; there was a distinct regional element to Biden's appeal, observable largely in the South. Neither does this mean that black voters who support Biden are "low information" or "conservative" or "establishment"; they're simply motivated by factors -- and fears -- that other candidates have yet to speak to as convincingly. (Sanders wasn't without minority support -- his came in the form of Latino voters -- but it wasn't enough to counter Biden's support.)

Biden was also propelled by older and more moderate voters across all the states he won on Tuesday -- so his support wasn't limited solely to black voters.

But the former vice president always knew the importance of having black Americans in his corner. Now, the rest of the country does, too.