Is Equality a Totally Empty Idea?

Professor Peter Westen's essay asserting that the concept of equality has no substantive content whatsoever usefully brushes aside much of the equal-protection rhetoric that, as Westen carefully explains, appropriately belongs to substantive due process. However, his absolutist position is open to challenge. I would like to posit one hypothetical case that I used in my classes when I taught Constitutional Law that I think contradicts Professor Westen's thesis. If it does, then there will be other cases as well, and his position cannot stand as the logically tight construct that he repeatedly asserts that it is.