The 'Alt-right' doesn't exist, anymore than the 'vast rightwing conspiracy' exists. Both were completely made up by the Clinton camp in late 2015.
Remember when Laura Ingram waved at the audience at the RNC, and the entire liberal online community accused her of doing a secret Nazi salute based on a selective still shot? People will see what they want to see.
The alt-right does exist, there are people who call themselves that.
http://bigstory.ap.org/article/c59982f8b8b74375924dc53b1da835f7/clinton-sees-trump-ties-alt-right-dystopian-ideologyClearly not something that Clinton made up.