Two congressional Democrats who are co-chairs on Joe Biden’s reelection campaign took to the airwaves Friday morning to defend the president against calls for him to withdraw from the race.

In separate morning TV interviews, Rep. Jim Clyburn of South Carolina and Sen. Chris Coons of Delaware said they remain firmly behind Biden.

Meanwhile, California Gov. Gavin Newsom, a Biden campaign adviser, batted down talk of him replacing the president on the ticket. 

Clyburn, whose endorsement of Biden four years ago has been credited with helping to propel him to the presidency, told NBC’s “Today” that Democrats should end the debate about whether Biden should continue to run following his devastating debate performance last month.

“The conversation should be over,” he said.

“The conversation should focus on the record of this administration, on the alternative to his election, and let Joe Biden continue to make his own decisions about his future,” Clyburn continued. “He's earned that right, and I am going to give him that much respect. If he decides to change his mind later on, then we will respond to that.”

Clyburn acknowledged that Biden sometimes “mangles words and phrases,” but he blamed that on the president’s childhood stutter. At the NATO summit Thursday in Washington, Biden introduced Ukrainian President Volodymyr Zelenskyy as “President Putin” before quickly correcting himself. Hours later, during his highly anticipated news conference, Biden referred to Vice President Kamala Harris as “Vice President Trump.”

But Clyburn insisted Biden “has one of the best minds that I've ever been around.”

“And so I would hope that we will focus on the substance of this man, rather than these sometimes the misspoken words and phrases, and how he has run this country,” the South Carolina congressman said.

Asked if he thinks Biden, 81, is the same as he was two years ago, Clyburn, 83, said, “No! I’m not the same Jim Clyburn I was four years ago.”

But he said with age comes greater wisdom and maturity. 

“When I became a man, I put away childish things,” Clyburn said. “Joe Biden has put away childish things because he has become a man. His opponent is still being a child.”

On CNN, Coons said he’s urging his Democratic colleagues to voice any concerns they may have about Biden’s candidacy directly to the president “and not work through their emotions and concerns in editorials and public speeches.”

Biden “has been listening,” Coons said.

The Delaware senator cited poll numbers showing there has been “no big movement in this race” after Biden’s debate showing, in which the president at times lost his train of thought. 

Nineteen congressional Democrats have called on Biden to withdraw from the race, but Coons said they represent only a fraction of members.

Coons called Biden’s performance at Thursday’s news conference “impressive.”

“Last night, he gave a 10-minute speech about our place in the world, the importance of NATO, how it contributes to our security and prosperity and then took a dozen questions,” Coons said. “And I just want your viewers to ask themselves this question: If Donald Trump had been on that stage for an hour last night asking questions from reporters about foreign policy, could he possibly have delivered the answers our president did? We all know the answer’s no.”

Possible replacements widely mentioned if Biden leaves the race have included Harris and Newsom.

In an interview set to air on “CBS News Sunday Morning” this weekend, Newsom said he deletes messages asking him about running.

“I’m all in [on Biden],” Newsom said. “No daylight.” 

CBS posted an excerpt of the interview Friday on social media.