The identical reasoning applies to trafficking with Libertarians. Apparently, this point was well understood, since none of the responses I received to the article even mentioned this issue. So I will expand on that subject to clarify what may still remain unclear. Yes, if evil is the irrational and the destructive. If the Libertarian movement were ever to come to power, widespread death would be the consequence.
Justice demands moral judgment.
It demands that one objectively evaluate Libertarianism, and act in accordance with that evaluation. And it demands that Libertarianism, like all such threats, be boycotted and condemned. Moral judgment, and not some pragmatic calculation of losses and gains, is what must precede any decision about whom to associate with. The moral is the practical. There can be no value in pretending that the irrational is rational.