Without socialist economics, libertarianism is extremely regressive, as it just means turning the economic power of the ruling class into the only power that exists. North American libertarianism is far right as fuck.

(If you want to see what libertarianism plus socialism looks like, google Errico Malatesta.)

I mean, how socially regressive is too regressive to be libertarian? They've been pretty clear on their stances with respect to immigrants and other minorities.