The man in black fled across the desert and the gunslinger followed.

I don't know what to tell people about Stephen King's Dark Tower series. The first few books of the 8 book series are great, and then the last few are just weird. Like, Salvador Dali's fever dream meets the last season of Lost meets that one John Ritter movie where he gets stuck in Satan's television weird.
And yet for me, and for millions of other Tower fans, it is so much more than the sum of its words. King has written things that are more clever, more entertaining, and more coherent; but he has never written anything more meaningful. 
I have serious misgivings about Sony's upcoming film adaptation. I can't even imagine how they're going to cram all eight crazy books into one 2-hour mainstream movie. What I do not have are grave misgivings about the film's star. Roland Deschain is a great character and epic badass Idris Elba is the perfect actor to play him.

On social media, a whole lot of Tower fans do have grave misgivings - about the color of Elba's skin. They're not racist, of course, it's just that having a black guy play a character who was originally written as white is blasphemy. Blasphemy is getting thrown around a lot. Filmmakers are "reverse racist" for taking a white man's job and giving it to a black man, and anybody who thinks different is just playing the "race card."

People who claim to love the books but are okay with this travesty aren't real fans at all (Stephen King must really hate these books since he's been on Team Elba since before the casting decision was final).
I wish I could understand these people on any level so I could explain to them why they're idiots. But I just don't. I get that they really, really believe they're not racist. But does any one of them throw a social media tantrum every time they cast another white guy as Jesus? Hell, people were mad that one time an Arab guy wrote a book about Jesus.

No fair! I'm not racist, I just hate Muslims!

And to think that giving a white character's role to a person of color is unfair requires you to pretty willfully ignore the fact that by every possible measure, actors of color are dramatically underrepresented in film and on TV. When the racial demographics on movie screens begin to approach the racial demographics of our nation, then we can start worrying about roles for white guys. 
I also don't get people who think that a film adaptation should, or even could be identical to the books. I got news for you, kiddies - 8 books ain't gonna fit in 2 hours and they're going to be changing a hell of a lot more than one character's skin color. Plus, nobody is complaining about Matthew McConaughey being cast as the man in black, even though McConaughey is clearly not a trans-dimensional warlock. They're probably going to have to scrap the battle with the Dr. Doom robots for copyright reasons, and it's almost certain Charlie the Choo Choo will not be played by an actual sentient evil train. You want an experience identical to reading the books, go read the books again.

Luckily, I have a solution for all the folks who just can't get past the skin thing. As you know, the books involve a lot of hopping between dimensions. So you can just pretend that this book is set in an alternate reality where Roland is black and you're not a racist crybaby. 

Quotation from The Gunslinger
Photo definitely not taken outside the Merry-Go-Round Museum.