Language is a social contract. We agree on the meaning of words and consequently we can communicate.
We agree that some words are offensive so that we can use them to offend. If “f*ck you!” was not offensive, then it would have no meaning when we said it to someone we were angry with.
Offensive words are generally determined in the aggregate, via all of the mechanisms of culture: Media, Communities, Families, Government, Entertainers, and so on.
So who is allowed to say the N-Word?
Generally, it is impolite to comment on someone who is overweight as being “fat.” A person who has weight issues may self-ridicule, but to address that person’s issues for them is commonly considered offensive or cruel.
Likewise, it is rude to call someone ugly or hideous if they are disfigured or unfortunately featured (whatever that may mean, after all beauty is in the eye of the beholder).
Weight and appearance struggles belong to the individuals that bare them.
So, I would say that the N-Word represents centuries of torture, murder, rape, ridicule, and exclusion endured by African-Americans, and therefore the word belongs to them.
The word was (and sadly still is) used as a weapon specifically against African-Americans. To defang the word, the Black Community over the last century has taken the N-Word from racists and claimed it as their own. This seems just.
The struggle is Black, the word is Black.
In short: America’s social contract regarding the N-Word is that African-Americans can use it however they see fit and it is simply off limits for other Americans.
Most all Americans agree to this contract, at least the ones who understand privilege and history. Even racists tend to fear the word because of how strong the national understanding has become, and how damaging the punishment for misuse.
Are there exceptions? There are always exceptions, but I’d say that even the exceptions are determined by the Black Community – which is also a nebulous concept, comprised of Families, Media, respected Celebrities, etc.
“But why do Black people get to say something and not me? That’s racist!,” says the ignorant person who is unable to understand historical nuance and the complexity of linguistics.
Using the N-Word assumes ownership of the word, and the majority of our modern society has decided that non-Black people simply don’t own it.
Even non-Black people who are extremely allied to the Black Community and given permission in their own Black social circles to use the word generally understand not to say it outside of those limited, friendly circumstances. One person may have a social contract with his or her friends, but this does not typically extend into the rest of society (until the issue has resolved once and for all everywhere in the country).
Will there come a day when anyone can use the word without offense? Will the N-Word ultimately share a status with other historically racist words that no longer offend anyone because the group of people the word insults is no longer disenfranchised? Perhaps.
But until that day, if I am asked: “Can non-Black people say the N-Word?”
I would say, “No. At least not until the Black Community says yes.”