They will attack a claim that is 100 percent factual and demonstrably so, but they won't deny that it's true, at least, they will not call it a lie. They will instead dance around the issue of the claims factual validity, if it's an accusation, they will refrain from actually denying it. Instead, they will attack it on moral grounds, it's hateful, or based in hate, it's an attempt to lend scientific validity to racist attitudes, which are regressive and best left in the past. They will say all manner of things like this, none of which even touch upon the reality that the claims are true. The common element of these weaseling around tactics is that they respond to facts with pure opinion, nothing that can be disproven or shown to be false. Nothing that is of any substance, and nothing that can be challenged in any way. The biggest example Is Noam Chomsky, who said that knowing the differences between racial populations is something only racists are interested in, and that this information has no use except to justify and embolden racism (besides the fact that these statements are false and irrelevant, what happened to "the truth is paramount, and is something that justifies itself?" I guess that only applied for the truths that you like and others hate, not the ones that you hate and others like). I can see why thet might rely on it, the same reasons that Penn and Teller used curses, insults, and other terms of abuse in place of calling people liars or deceivers, because calling someone dishonest is litigateable, while just expressing a negative opinion on them is not. It's an effective tactic, but I've found an effective counter. Pretend to others that they are attacking the claim by denying that it's true, act as if they had said something that could be shown to be false in no uncertain terms, then show it to be false that your claims are untrue. Finally act as if they got it wrong, and call into question their position on anything else. I did this with a liberal friend of mine, and he responded by saying that I didn't read the article (I had, he hadnt), later on, he got back to me by saying that the article never said the claims were false, only that they were morally reprehensible to point out (this coming from soneone who used to think that the truth was more important than any cost that comes with revealing it, something that I still beleive in). I then got him to think about what he had revealed about his favorite source of information.