The Libertarian party was taken over by MAGA Republicans (they called themselves the Mises caucus). And they have basically destroyed it.

Last election cycle they had Trump speak at their national convention, if that gives you an idea of how complete it was.

So this is basically a MAGA Republican puppet calling for assassinating Democrats. Actual Libertarians calling for the assassination of public officials would surprise me. I don't think MAGA Republicans calling for the assassination of Democrats would surprise anyone.