"At one of their debates, Mr. Biden accused Mr. Trump of treating the Justice Department like his 'own law firm' in the suit, filed against him by the writer E. Jean Carroll."

"'What’s that all about?' he sarcastically asked. But on Monday night, nearly eight months after Mr. Biden’s attack, his own Justice Department essentially adopted Mr. Trump’s position, arguing that he could not be sued for defamation because he had made the supposedly offending statements as part of his official duties as president. In a brief filed with a federal appeals court in New York... the Biden administration’s Justice Department, now led by Attorney General Merrick B. Garland... said that when Mr. Trump had denied raping Ms. Carroll, through the White House press office or in statements to reporters in the Oval Office and on the White House lawn, he was acting within the scope of his office. 'Elected public officials can — and often must — address allegations regarding personal wrongdoing that inspire doubt about their suitability for office,' the department lawyers argued, adding, 'Officials do not step outside the bounds of their office simply because they are addressing questions regarding allegations about their personal lives.' Ms. Carroll’s lead lawyer, Roberta A. Kaplan, reacting to the new filing, said that as 'horrific' as the alleged rape was, it was 'truly shocking that the current Department of Justice would allow Donald Trump to get away with lying about it.'"

From "Biden Justice Department Seeks to Defend Trump in Suit Over Rape Denial/Donald Trump is facing a defamation lawsuit brought by E. Jean Carroll, who has accused Mr. Trump of raping her" (NYT).

It's not about Donald Trump anymore. It's about presidential power, and the new President needs and wants to defend that power. Presidents are attacked, often about personal matters, and they defend themselves. That turns into a defamation suit. That's going to happen again and again if it's allowed. As President, Joe Biden can easily see "What’s that all about?"