Complex sentence: The'Alt-Right' is a right-wing movement including ideologies that are an alternative to mainstream American conservatism, which has "more in common with European far-right movements than American ones" and is influenced by the Dark Enlightenment and white nationalism.
Split into simpler sentences: The'Alt-Right' is a right-wing movement including ideologies that are an alternative to mainstream American conservatism. It has "more in common with European far-right movements than American ones" and is influenced by the Dark Enlightenment and white nationalism.