Rep. Jim Clyburn’s endorsement gave Biden some serious momentum in South Carolina

A last-second endorsement from South Carolina Rep. Jim Clyburn, the third-ranking Democrat in the House, appears to have given former Vice President Joe Biden a substantial boost in his decisive victory in South Carolina’s presidential primary on Saturday.

According to exit polls conducted by Edison Research, 61 percent of Democratic voters said Clyburn’s endorsement was an important factor in their decision. And 27 percent of voters said the endorsement was “the most important factor” in their candidate choice.

The impact of Clyburn’s coveted endorsement on voter thinking underscores how even in an era in which party elites have declining influence over primaries, a respected politician can still have sway over voters.

Clyburn has represented South Carolina for nearly three decades, and is the highest-ranking African American politician in Congress. He’s widely considered a kingmaker in South Carolina, and his quadrennial “World Famous Fish Fry” is an iconic institution on the Democratic presidential campaign trail.

The timing of Clyburn’s endorsement for Biden, which came three days before the primary, was crucial — perhaps even more so because of the number of undecided voters in the state just days ahead of voting. A Monmouth University poll released one day before Clyburn’s endorsement, for instance, found 15 percent of likely primary voters were undecided.

According to a Washington Post exit poll, an even greater number of voters — 37 percent — decided on their candidate in the last few days before the primary; 48 percent of those late-deciding voters went to Biden.

Biden’s victory, in which he beat national frontrunner Sanders by nearly 30 percentage points, could potentially revive a campaign that has underperformed in early state contests and struggled to gain traction.

And the candidate made it clear who he believed was responsible for the win in his victory speech Saturday night, saying, “My buddy Jim Clyburn, you brought me back!”

This is the first primary of the 2020 season Biden has won — and the first primary in three presidential runs that he’s ever won — and it is a particularly important one: South Carolina is a crucial bellwether for the South, and it’s possible that other Southern states with similar demographics (like Alabama and North Carolina) could go the same way.