They're funny.
And like everything else they spout, wrong. I'm convinced that they are incapable of telling the truth in anything.
Your assumption is correct. Liberalism truly is a disease. They can't tell reality from fantasy, and as Kevin said, they tell the same lies over and over and over until they believe it to be truth.
There is, however, a cure for SOME. I myself was saved from the disease this way. You have to open your eyes to make it work, though.