Since when is literacy a right? It's a public benefit, but a constitutional right? That's a weird concept to me. Not to downplay its importance, as it's extremely important, but why should it be a fundamental right? Even the UNs Universal Declaration of Human Rights does not list literacy as a right. It does list education, but does not specify further other than saying education at an elementary school level. Even according to that Detroit is in compliance.
Now, it's a damn shame and a public embarrassment and needs to be fixed, that's for sure.