I could just as easily say that whenever one argues with a non-libertarian, he or she lays out an endless series of straw men.

See how that works? "Your argument doesn't accurately represent my viewpoint" is what both No True Scotsman and straw men are about. So rather than opting out of an argument by calling "logical fallacy" on someone, why not clear up the definitions and be sure of what each other are talking about?

That's odd. Can you give me an example of a common libertarian No True Scotsman argument?

Well, it's not really a pure free market system, so it doesn't count.

you do realize that is a valid argument though, right? The core concept of the no true scotsman argument is the wishy-washy definition of what is being debated. He isn't a true scotsman because a true scotsman would wear a kilt! something like that. If the definition of scotsman is "wears a kilt" the same way a libertarian would say "pure free market" then it is totally valid.

He may wear a kilt, but he doesn't play the bagpipes, so he's no true Scotsman.

Probably referring to you calling the US health care system free market...

Herbert Hoover was a huge activist big government Keynesian.