White House officials and Democrats fanned out to defend President Biden’s mental fitness on Sunday, reflecting the rising anxiety in the president’s administration over a special counsel report that fueled concern about his age.

“This is a report that went off the rails,” Bob Bauer, Mr. Biden’s personal lawyer, said on CBS’s “Face the Nation.” “A shabby work product.”

The report, released on Thursday, cleared Mr. Biden of criminal wrongdoing in his handling of classified documents after leaving the vice presidency. But the special counsel in the case, Robert K. Hur, characterized Mr. Biden, 81, as a “well-meaning, elderly man with a poor memory” who had “diminished faculties in advancing age.”

Democrats have gone on the offensive to discredit what they say is a partisan hit that potentially violated Justice Department policy, specifically taking issue with the descriptions questioning Mr. Biden’s memory.

Alejandro N. Mayorkas, Mr. Biden’s homeland security secretary, said on NBC’s “Meet the Press” that “the responsibility of a federal prosecutor is to investigate and learn the facts and apply the law to those facts.”

“The special counsel did this in the case, made a conclusion that there is no case — case closed — then made gratuitous, unnecessary and inaccurate personal remarks, and those are improper,” Mr. Mayorkas said.