As for Mr. McConnell, it is not clear what he could do to block a nominee, after he personally engineered a Senate rule change in 2017 to ensure that a Supreme Court pick can be confirmed with a simple majority vote. On Thursday, there was talk that by withholding a quorum for voting on a nominee, Republicans on the Senate Judiciary Committee could block a vote. But even that seemed far-fetched, since such a provocation could force Democrats to unite around a rules change to bring the nominee to the floor.
If Republicans join in opposition to his nominee, Mr. Biden will need the support of all 50 Democratic and independent senators to win her confirmation, and if Mr. McConnell labels the president’s pick “radical,” it could ratchet up pressure on the party’s centrists to withhold their backing.
One potential object of a pressure campaign would be Senator Kyrsten Sinema, Democrat of Arizona, whose positions so far have helped block a far-reaching voting rights bill and stymie a social safety net and climate change measure. But Ms. Sinema has been relatively liberal on Supreme Court nominees.
“I look forward to fulfilling my constitutional duty to provide advice and consent by thoughtfully examining the next nominee based on three criteria: whether the nominee is professionally qualified, believes in the role of an independent judiciary and can be trusted to faithfully interpret and uphold the rule of law,” she said on Thursday.
Mr. Clyburn’s campaign is unusual, since as a House member he has no vote on the eventual nominee. But that did not stop him from pressing the case for Judge Childs of the U.S. District Court in South Carolina, who is a former circuit court judge in the state’s capital, Columbia, and a labor law expert.
“There’s nobody sitting on the Supreme Court today that can tout the background, experience, life and profession that Michelle Childs would bring to the court. It’s just that simple,” Mr. Clyburn said at the Washington Post event.
Mr. Biden first made his pledge to nominate an African American woman to the Supreme Court in South Carolina before that state’s critical early primary, at Mr. Clyburn’s urging. But Judge Childs is not the most experienced jurist in the potential pool of nominees.
Luke Broadwater contributed reporting.