No, libertarians are not:
Spencer has attempted to wring as much publicity from the incident as possible—he tweeted about it no fewer than 40 times, by my count. In his mind, libertarians are “lolbertarians” who need to “accept the reality of race” and get serious about “white replacement.” To the extent that his only goal in life is to garner more attention for his fringe worldview, I suppose the stunt was a success—here I am writing about it. Congrats to you, guy who thinks “the United States is a European country.”
In any case, the incident should make abundantly clear that the alt-right’s racism is incompatible with the principles of a free society. Libertarianism is an individualist philosophy that considers all people deserving of equal rights. In contrast, Spencer is a tribalist and collectivist whose personal commitment to identity politics vastly exceeds the left’s.
Yes. “Alt-Right” is just another variation on Left.