I think a pretty good proportion of libertarians are libertarians because they're instinctive contrarians, they enjoy status games and esoteric arguments. You therefore need to present things as out there, and give them arguments they've never heard before, even if they're not yours. You also need to distance both yourself and them from stereotypical veg*ans, go in for a bit of hippy punching over their crazy environmentalism or something. Essentially, if eating meat is the norm, and standard vegetarianism is the first contrarian position, most libertarians will think of themselves one level above that, that vegetarians are naive little girls. You need to take it even past that level, to assure them that they can be above their peers without being mistaken for one of ‘those’ vegetarians.
The nearest I’ve found to is is broadly the arguments laid out in essays here, especially the parts on wild animal suffering and environmentalism9. It ticks all the boxes, hippy punching, esoteric and a refreshing lack of design. The focus on data is also worthwhile, since I imagine a good proportion of libertarians are pretty high systemisers.
1 One of my top 10 favourite facts is that homophobia is probably more heritable than homosexuality. Born this way indeed. ↩
2 Don’t worry guys, all must have prizes, you apparently perform better at systemising in the same theory. ↩
3 My favourite general explanation is in this paper.↩
4 Nozzle is a beautiful word. ↩
5 Though this may look like I reasoned things through this way, I started here and wrote backwards, post hoc rationalising my instinctive beliefs. Behind the curtain.↩
6 Though not vegans, interestingly. Are there different mechanisms at play? ↩
7 Well, almost nobody. ↩
8 Answers on a postcard.↩
9 Thanks to Ben (@bswud) for linking me to this.↩