Many Democrats now believe that adding seats to the court is the urgent remedy, an extraordinary step that has not been seriously contemplated since the administration of Franklin D. Roosevelt. They argue that the court’s legitimacy has already eroded amid the Republican confirmation maneuvers of the last four years…

“My inclination is to think that he would just see that as making it more political instead of making it less political,” said Cynthia C. Hogan, a former Judiciary Committee aide who helped lead Mr. Biden’s search for a 2020 running mate. “I think he wants to restore the court to its earlier place of respect.”…

Interviews with more than a dozen former colleagues, aides and other contemporaries from his earlier court clashes present Mr. Biden as a conflicted combatant in the judicial trenches, negotiating the constant tug between precedent and pragmatism, convention and conviction.

During the Democratic primaries last year, as activists pressed him to embrace the court expansion proposals, Mr. Biden dismissed the idea out of hand, predicting that “we’ll live to rue that day.” But he has recently taken a more ambivalent stance.