As progressives (leftists) see it, there is no chance that they are wrong, misguided, mistaken, or incorrect (much less confused) about anything they believe. They are right, and that's all there is to it. The only question, in their minds, is why anyone would hold a different view of things. This truly puzzles them. The only explanation they can come up with is that those who disagree with them (i.e., don't share their beliefs or values) are badly motivated. They're racist, sexist, homophobic, xenophobic, bigoted, prejudiced, nativist, restrictionist, intolerant, Islamophobic, and either evil or stupid (or both). In Jeremy Bentham's terminology, they have a "sinister interest."
You will recognize this as name-calling rather than arguing. (We might think of it, sarcastically, as argument by name-calling.) Progressives have lost the ability to argue. To argue is to respect your interlocutor as a person, and progressives have no respect for those who disagree with them. It's about winning, not persuading. The aim is to crush opposition, not discover the truth. Progressives want power, and will do whatever it takes to get it. This is what I mean when I say, as I often do, that to a progressive, the end justifies the means. See here for an illuminating essay.
