Equality is only possible if everyone has access to the same opportunities, in the same way. Many forget that equality does not only pertain to access, but also to the quality of the product they have access to. Once separation is implemented, it is impossible to insure equal quality for both sides, because the notion of separation is based on a racist thought process. Those who implemented this strategy wanted to protect themselves from a race and ethnicity they believed were lesser than themselves. Therefore, there is no way to create equality if the basis for the separation was rooted in a superiority complex.
Separation and equality cannot coexist. Those in support of a separate, but equal society bask in privilege and have never experienced a life where they do not have access to the best resources or opportunities. Separate, but equal can never be successful because it is inherently based on racism.