Granted, that seems to be the thrust of it, and I kind of missed it at first, looking at what I thought funny.
I don't sense there is a "Buchananism" as a ideology of identity, in the same way their is the phenomenon of "Neo-Conservatism." Buchanan is one guy. I agree with many of the things he says, some not. There is a reflexive distaste for Jewish people in his views, and that seems to be a better mark that distiguishes him, Taki and Raimondo (hey, great press Justin!) as being of the same mind, rather than other views he espouses, but which many share. The other "Buchananite" mark of distiguishment I see is the critique of mass immigration as a cultural threat. I think the threat to the culture comes from the cult of multiculturalism inculcated into immigrants by teachers, an anti-integration ideology of enforcing difference and animosity, a direct attack on an American identity.
If there is a widely held and coherent "buchananism" such would support the construction of the forces at play by this writer. But I don't see such.
BTW, the way I see the "neo-con" movement is that they were lefties that substitute the cult of statism with the cult of the CEO, funded and directed not by the USSR and union front organizations, but executives of corps with their front group NGOs and "think tanks." Nothing has changed, it's just idolization for the personal gain of one elite for another putatively on a different side of the political spectrum. He points out that "Buchanites" may become "left". I don't know, not many examples. The best example of changing putative political idenities while staying effectively the same are neo-cons themselves.