Put it in its historical context. Tolkien wasn't writing his English mythology to be anti-black, anti-Irish, or anti-anybody else. He was writing it because, as scholar of Anglo-Saxon literature, he saw that something had been lost to history, and wanted to create something to fill in the blank. He was creating an English language equivalent to the Icelandic sagas or the Finnish Kalevala, to fill out the lost English world you can glimpse in Beowulf or Sir Gawain and Green Knight.
It's very much in the context of late 19th century romantic nationalism. You hear "race" or "nationalism" and think of oppression and jackboots, that it means hating the other. I think of the revolutions of 1848, when European romantic nationalist and liberals were overthrowing the multiethnic empires of old, to set up self-ruling nation states. To me, Hungary for the Hungarians, Finland for the Finns, etc. wasn't evilly fascist, but progressive -- and it was both a political and artistic movement, with rediscovery of folk art, folk music, and pre-Christian mythology that had been considered backward and were endangered at the time. It's closer to the "locavore" movement than fascism . . .
