Libertarians get a lot right - a whole lot. But immigration isn't one of them. They ignore the unlevel playing field that libertarian theory presumes to be non-existent. But it's only non-existent in a completely libertarian world - otherwise it's presumption is dangerously naive. That's why libertarianism only works best internally, where a level playing field can at least be theoretically created. Against international problems though, it would lead to slaughter.
I’m not too fond of their goals of “gay marriage” and adoption and unrestrained military homosexuality and unrestrained abortion including late term abortions among other things either.