Did not his Mongols, the Rohirrim, save the day?
His tall, blonde-haired and blue-eyed Mongols? Interesting thesis you have there.
In my opinion he fell victim to the classic blunder of sci-fi/fantasy writers: he was too in love with his world, to the detriment of the story that happened in it. The Fellowship of the Ring was all right, but the other two books bored me to tears.
SFF authors take note: readers don’t care about your world unless interesting things are constantly happening to sympathetic people in it.
Actually, his blonde, blue-eyed mongols can only save the day because they are themselves rescued from certain doom by his grass-skirt-wearing, bone-through-the-nose “natives”. 
Though admittedly, they got cut from the movie version.
Readers with short attention spans, anyway.
No doubt that blunder explains his lack of popularity and success.
Hey, he invented that blunder!
I suspect Tolkien was thinking more along the line of Russian steppe Goths.
What other people who were horse-borne nomads ranging over significant distances were there in the real world? And the Mongols traded with the Vikings, so plenty of blue-eyed blonde slaves went East.
Great Plains Indians?
They didn’t get to do that for long, though.
The Rohirrim were hardly nomads at that point in the Third Age, in Tolkien’s fictional universe.
The Rohirrim are Anglo-Saxon/Germanic in derivation
It seems to me that the Rohirrim were basically vikings, transplanted from ships to horses. According to Wikipedia, the Rohirric language was represented by the Mercian dialect of Anglo-Saxon. I have read some sources claiming that he often fantasized about what Britain would have been like if the English had had cavalry at the Battle of Hastings.
It’s been a while since I read it, but I don’t remember the descriptions of the Southrons and the Easterlings being detailed enough that you could definitively ascribe any Terran race to them.
More problematic, when you consider that it was written during or shortly after World War II, is that his descriptions of Orcs bear a strong resemblance to wartime caricatures of the Japanese. They are short, bow-legged, and yellow-skinned, with weak eyes and curved swords. In my opinion, this was probably not conscious racism. He grew up in a culture where tall-and-blonde was considered beautiful, and short-and-dark was considered less so. If someone had pointed out the racial angle, I think he would have been horrified, and gone into a flurry of re-writing. But few people were interested in such things until a decade after LOTR was published.
As for the Literati, the most persistent criticism I have noticed is that ivory-tower Marxist wannabes think he is a reactionary. Frodo, Merry, and Pippin are too bourgeois, and the proletarian Sam is not plotting revolution.
I’m not certain that race, per se, was even something he thought about - at least not in those terms. He hardly described the common physical features of many of the peoples visited. I think Rohan was most described that way, probably because they were basically Norse Mongols.
But he was marvelously unclear about the ethnic differences of the different peoples. If the peoples to the south of Gondor were swarthier than those to the north, it’s not especially clear or clear how much. Heck, I always got the idea that Gondor was itself something of an ethnic mix, and that Aragorn was vaguely Italian-Romanesque. Physically speaking, the English are hardly represented at all, being mostly the vaguely-Caucasian Hobbits and Arnorians, of whom basically see nothing but the Shire and Bree and who aren’t shown as especially mighty or aware of a racial identity.
All in all, it really seems like something people bring to the story, not anything they get out of it.
…and even that list is incomplete. No mention of any of the Scythian/Sarmatian groups for example.
Scythians are listed under “Pastoralists” in the “Middle East” section, although it would make more sense to list them under “Asia”, I suppose.
Anyway, just because the Mongols are the only horse-riding nomads you’ve ever heard of doesn’t make them the only ones that ever existed. And the Rohirrim aren’t very much like Mongols. They’re obviously and literally Anglo-Saxons transplanted to the steppes and given horses.
If you want to argue they aren’t Mongols o the grounds of a great diversity of nomads, then fine. But Anglo-Saxons they are not. Not even close. They are far close to the Danes who kind-sorta kicked the crap of the Anglo-Saxons, took over and who in practice eventually ruled over it as the Normans.
Or to put it another way, they’re Vikings with herds instead of ships.
Oh, yeah.
Obviously not your fault but that makes no sense whatsoever :). You’d need a pretty generous definition of the ME to ever get a few of those groups even included on the far periphery, let alone central to their range. Eh, whatever - it’s wiki-town :D.
The thing is, Tolkien was only accidentally a writer of epic fantasy. All the early writing was simply world-building for the purpose of creating peoples to speak the languages he was inventing. So of course he was in love with his world. That was always the point of his writing. The stories were mostly incidental.