Several Democrats in Congress spoke out on Monday against President Biden’s decision to issue a broad pardon of his son Hunter Biden, criticizing the action as one that would further erode Americans’ already waning faith in democracy and the rule of law.

Many Democratic lawmakers, particularly progressives, have defended Mr. Biden’s move as the justified action of a concerned father who fears that President-elect Donald J. Trump will abuse his power to follow through on his threats to seek retribution against his rivals. But others, especially moderate members of Congress, said the president’s decision to pardon Hunter Biden — which he repeatedly vowed he would not do — would cause further damage to democratic norms.

“I’m disappointed this was the decision that he landed on here,” Representative Jason Crow, Democrat of Colorado, said of President Biden in an interview. “He promised he would not do this. I think it will make it harder for us going forward when we talk about upholding democracy.”

Representative Marie Gluesenkamp Perez, Democrat of Washington, said the president’s move offered proof of a two-tiered justice system that treated the wealthy and politically powerful differently from everyday Americans.