Washington (CNN) South Carolina Rep. James Clyburn on Sunday said he'll endorse a 2020 Democratic presidential candidate after Tuesday night's Democratic debate -- just three days before the state's primary, a key early contest in the party's nomination process.

Clyburn, the House Majority Whip and a key South Carolina voice, has not yet made a public endorsement in the race but said he'll announce his decision Wednesday morning. The third-ranking Democrat in the House told CNN's Fredricka Whitfield that he has known for some time who he was going to support, but that he had promised the Democratic National Committee and the South Carolina debate sponsors he would not "get out in front of the debate and render any kind of confusion about it."

"I'm going to reveal exactly who I think is best and why I think that person is best," he said of his planned Wednesday announcement. "I hope that there would be a majority of South Carolinians agreeing with me."

Clyburn made similar comments to ABC and NBC earlier Sunday, saying that while he accepts Vermont Sen. Bernie Sanders as the 2020 Democratic frontrunner, if the state's primary election was held tomorrow, former Vice President Joe Biden would capture more votes from African Americans than any other Democrat.

"Well, I would accept the fact that he's the frontrunner. I want South Carolina to have its say before I talk about who would be the odds on favorite," Clyburn said during an interview on NBC's "Meet The Press."

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