A Republican-appointed judge on Thursday denounced as “shameless” the attempts by prominent Republican politicians to recast the Jan. 6 riot in a positive light, including by portraying the Trump supporters who sacked Congress as having done nothing wrong and by calling those convicted of crimes political prisoners or hostages.

“In my 37 years on the bench, I cannot recall a time when such meritless justifications of criminal activity have gone mainstream,” wrote Judge Royce C. Lamberth of the Federal District Court in Washington. “I have been dismayed to see distortions and outright falsehoods seep into the public consciousness.”

The remarks, made in a seven-page filing that Judge Lamberth described as notes for what he had said on Thursday at a resentencing hearing for a Jan. 6 rioter, amounted to a scathing and extraordinary broadside against a vast web of conspiracy theories and falsehoods about the Capitol attack that have permeated the right.

Criticizing the rioter, James Little, for displaying “a clear lack of remorse,” the judge used the occasion to also “set the record straight” about what he portrayed as a broader disinformation campaign, citing the evidence he has absorbed from presiding over many Jan. 6 prosecutions.

“I have been shocked to watch some public figures try to rewrite history, claiming rioters behaved ‘in an orderly fashion’ like ordinary tourists, or martyrizing convicted Jan. 6 defendants as ‘political prisoners’ or even, incredibly, ‘hostages,’” wrote Judge Lamberth, a 1987 appointee of President Ronald Reagan. “That is all preposterous. But the court fears that such destructive, misguided rhetoric could presage further danger to our country.”

The judge did not name the public figures he accused of spreading disinformation. But both former President Donald J. Trump and Representative Elise Stefanik of New York, the fourth-ranking House Republican, have used the term “hostages” to describe the people being prosecuted for trespassing in the Capitol and assaulting police officers as part of the mob that sought to block Congress from certifying Joseph R. Biden Jr.’s Electoral College victory.