it’s older than that...
In November 2008, Paul Gottfried addressed the H. L. Mencken Club about what he called “the alternative right”.
Thanks! I know that he says he coined the term, or jointly coined it with Spencer.
Spencer, of course, claims sole invention. He's an egoist, so not surprising.
A great article about Paul Gottfried was published recently in the Jewish (liberal) periodical Tablet. Here is the link:
The Alt-Right’s Jewish Godfather: How Paul Gottfried—willing or reluctant—became the mentor of Richard Spencer and a philosophical lodestone for white nationalists By Jacob Siegel.
It provides a pretty good history of the Alt-Right, too for anyone else still on this thread who would like a well written piece on them by someone outside the movement who is actually trying to report, not throw rocks.
There is some giant irony there -- that the leading new-age anti-Semitic philosophy has a Jewish godfather. All the fashy neos, worrying about Jewish influence and control are actually echoing an old Jewish professor. Someone upstairs has a sense of humor.