Another type of bad argument widely used in politics is guilt by association. Someone who calls himself socialist / conservative / libertarian said something stupid and or racist. Oh My God, all insert ideology are stupid and or racist. The fact of the matter is that each ideology attracts a wide variety of people.
Unlike being Scottish, political affiliation is something based solely on your own claims, not some objective fact (like being cheap or wearing a skirt and producing noise out of bagpipes.) Off course, if 75% of members of a certain ideology hold some view, it is not an issue to use association. After all if you differ in opinion to 90% of the members (see how the numbers change from sentence to sentence? Neat trick) of a movement, there isn’t much sense in identifying with it.
This is significant for libertarians because all sorts of different kinds of fringe movements are going to be attracted to some degree to libertarianism, because libertarianism is the one political philosophy that endorses allowing such fringe movements the freedom to practice their fringe beliefs without interference, as long as they do not use force against others.
Libertarians are some of the few saying it should be legal for people to privately discriminate. To be clear, people always discriminate anyway, and to pretend otherwise is ridiculous. A political philosophy that stands for genuine legal and social tolerance of varied belief systems is going to be seen as an ally and defender of those belief systems.
What's important is to remember and clearly state that defending a bigot or a racist’s right to be bigoted and racist, in his private life as long as he does not aggress upon others, is not agreeing with or endorsing those views. It can be quite the opposite, but that is the point of tolerance, as it is not difficult to tolerate the un-offensive.
It is very annoying to constantly need the use of disclaimers to avoid guilt by association. Whenever someone defends right to free speech, they must say “I do not agree with”. Well this should go without saying, that the mere fact you defend someone’s right to say something does not in any way mean you agree.
Libertarians can and should call out these people on their bullshit. But they should also keep tolerating them as long as they are not violent. In the end, it is their right.