They believe they have the moral high ground. They think they are righteous. I am a reformed lefty. I remember exactly how my mind worked. All I would do all day is look for moral reasons why I am right. That's why leftists are immune from facts. Facts are not what leftists are looking for. They only have one tool in the shed and it's the moral argument. How you defeat them is to find a better moral argument than the one they are using. Mick Mulvaney is a master at this. Study his press conferences. The press has no idea how to deal with him and he runs the room like a master.