When it comes to discussion the position of the conservatives and libertarians is often: "The liberals are well-meaning people though misguided".
The position of liberals is: "Those guys totally agree with our theories and views in private (how could those ever be wrong!), but publicly they say lies they do not believe in out of greed or vested interests".
That makes for an easy discussion. "There is no need for me to examine your arguments since I am convinced you are intellectually agreeing with me anyway but just pretend you don't."
So they just concentrate on guessing the reasons you would lie - like being an exploiter, a racist, an opressor, a nature despoiler, etc.
miko