Nobody’s going to deny that, as it’s conventionally depicted, Middle-Earth - the setting of The Hobbit and The Lord of the Rings - is awfully monochrome. In art, basically everybody is drawn as white, and all major depictions in film have used white actors.
When this state of affairs is questioned, the defences typically revolve around “accuracy”, which can mean one of two things: fidelity to the source material, and the internal consistency of the setting. Being concerned primarily with languages and mythology, Tolkien left few clear descriptions of what the peoples of Middle-Earth actually look like, so in this case, arguments in favour of the status quo more often rest on setting consistency.
Of course, we need hold ourselves neither to fidelity nor to consistency - the author’s dead, and we can do what we want. However, what if I told you that there’s a reasonable argument to be made from that very standpoint of setting consistency that Aragorn - the one character you’d most expect to be depicted as a white dude - really ought to be portrayed as Middle Eastern and/or North African?
First, consider the framing device of Tolkien’s work. The central conceit of The Lord of the Rings - one retroactively extended to The Hobbit, and thereafter to later works - is that Tolkien himself is not the story’s author, but a mere translator of writings left behind by Bilbo, Frodo and other major characters. Similarly, Middle-Earth itself is positioned not as a fictional realm, but as the actual prehistory of our own world. As such, the languages and mythologies that Tolkien created were intended not merely to resemble their modern counterparts, but to stand as plausible ancestors for them.
Now, Aragorn is the king of a tribe or nation of people called the Dúnedain. Let’s take a closer look at them in the context of that prehistoric connection.
If the Dúnedain were meant to be the forebears of Western Europeans, we’d expect their language, Adûnaic, to exhibit signs of Germanic (or possibly Italic) derivation - but that’s not what we actually see. Instead, both the phonology and the general word-structure of Adûnaic seem to be of primarily Semitic derivation, i.e., the predominant language family throughout the Middle East and much of North Africa. Indeed, while relatively little Adûnaic vocabulary is present in Tolkien’s extant writings, some of the words we do know seem to be borrowed directly from classical Hebrew - a curious choice if the “men of the West” were intended to represent the ancestors of the Germanic peoples.
Additionally, the Dúnedain are descended from the survivors of the lost island of Númenor, which Tolkien had intended as an explicit analogue of Atlantis. Alone, this doesn’t give us much to go on - unless one happens to know that, in the legendarium from which Tolkien drew his inspirations, the Kingdoms of Egypt were alleged to be remnant colonies of Atlantis. This connection is explicitly reflected in the strong Egyptian influence upon Tolkien’s descriptions of Númenorean funereal customs. We thus have both linguistic and cultural/mythological ties linking the survivors of Númenor to North Africa.
Now, I’m not going to claim that Tolkien actually envisioned the Dúnedain as North African; he was almost certainly picturing white folks. However, when modern fans argue that Aragorn and his kin must be depicted as white as a matter of setting consistency, rather than one of mere authorial preference, strong arguments can be made that this need not be the case; i.e., that depicting the Dúnedain in a manner that would be racialised as Middle Eastern and/or North African by modern standards is, in fact, entirely consistent with the source material, ethnolinguistically speaking. Furthermore, whether they agreed with these arguments or not, any serious Tolkien scholar would at least be aware of them.
In other words, if some dude claims that obviously everyone in Tolkien is white and acts like the very notion of depicting them otherwise is some outlandish novelty, you’ve got yourself a fake geek boy.
(As an aside, if we turn our consideration to the Easterlings, the human allies of Sauron who have traditionally been depicted in art as Middle Eastern on no stronger evidence than the fact that they’re baddies from the East, a similar process of analysis suggests that they’d more reasonably be racialised as Slavic in modern terms. Taken together with the preceding discussion, an argument can be made that not only is the conventional racialisation of Tolkien’s human nations in contemporary art unsupported by the source material, we may well have it precisely backwards!)