How is it possible to criticize the right for saying things that are so blatantly untrue that only someone quite foolish would believe them? The right does not

How is it possible to criticize the right for saying things that are so blatantly untrue that only someone quite foolish would believe them? The right does not deserve credit or blame for this. I have concluded that much of the role of political parties is to pretend that they are vastly different from the other party and to build narrative around that notion, when in fact they are mostly identical except for their historical relationships with various interest groups / donors.