Often I'll take an explanation of libertarianism and post it here, reflecting on that fact that by that definition 90% of the Western world is libertarian (so why can't they get Paul nominated or Johnson elected?).
It may seem like griping, but of course the real point of going through things like that is to get at the heart of differences in belief. If we take William James's view that there is no difference that doesn't make a difference, and if we observe no difference in a view on something, then that probably doesn't really get to the heart of the distinction of libertarianism. We've got to dig into more fundamental differences in the use of language.
Another option, though, is that common premises are assumed to be different because different groups of people take those premises in different directions. This came to mind when I read Jason Brennan's recent post at BHL on whether libertarians think all politicians are "selfish" or "evil". He writes:
"There’s a stereotype that libertarians think politicians and other government agents are selfish sociopaths, out for themselves.
Libertarians oppose romantic ideas about government. People are people. Handing someone a gun, calling him boss, and charging him with a noble goal will not transform him into a saint. Libertarians are skeptical that those in power will want to use their power to do good[...] Libertarians do not assume that soldiers or police officers are more saintly than the rest of us. In fact, libertarians tend to stress that political power attracts people who want to exploit that power for their own private ends."
My first thought when reading this was (once again), "but we all believe that, so this doesn't tell me much about libertarianism". I don't think this is a difference in language, though (in the way that libertarians use words like "liberty" very differently from a lot of people). I think the whole point is that almost all of us believe this, but we draw different conclusions from it. Most of us don't think this sort of thing warrants draconian restrictions on what we can try to achieve collectively (although it certainly calls for some restriction). Libertarians often take this point and extrapolate it out considerably in a way that doesn't seem well justified to the rest of us.
That is a real difference, of course. A difference that makes a difference.
What libertarians shouldn't do is go around thinking that the rest of us have romantic ideas about government just because we don't draw the same ultimate conclusions about the implications of that fact that you do.
James Buchanan, take note. It is not too late to retract some of your earlier scholarship inappropriately imputing this view to others.