What makes you think libertarians support either of those ideas?
You have a point: since there is no unified libertarian manifesto (not all subscribe to the von Mises one), one cannot tell; individual prominent libertarians (self-professed) seem all over the place on such matters. For example, the United Kingdom Independence Party calls itself libertarian, but while opposing gay marriage on the religious plane, it supports gay civil unions.
>> What makes you think libertarians support either of those ideas?
Unfortunately the Libertarian Party platform has defined what it means to be ‘libertarian’. I’ve grown tired of defending the libertarianism that I believe is something quite different especially concerning migration and morality.