House Majority Whip James Clyburn (D-S.C.) said Sunday that former Vice President Joe Biden Joe BidenMomentum growing among Republicans for Supreme Court vote before Election Day Trump expects to nominate woman to replace Ginsburg next week Video of Lindsey Graham arguing against nominating a Supreme Court justice in an election year goes viral MORE may have suffered in early presidential primary voting contests after not doing enough to sway voters during the early debates.

"I've heard from a lot of people that they thought that Joe Biden could have done more to engage on the -- during the debate, thought he could have done more to say why he would be deserving," Clyburn said on NBC's "Meet the Press."

"So I think he suffered from that. He didn't do enough."

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"So all of this changes when you only have six people," Clyburn said, adding that Tuesday night's debate in South Carolina will "be totally different."

Clyburn said he will endorse a candidate Wednesday morning after the debate.

Biden came in a disappointing fourth and fifth in the Iowa and New Hampshire nominating contests before rising to second place in Nevada.

Clyburn said he expects the Tuesday night debate will have an impact on how voters go to the polls on Saturday.