The outcome is right, but once again, Justice Kennedy’s efforts to produce something lasting and profound is a failure, and results in an opinion easy to ridicule, and lacking the logical infrastructure necessary to support the conclusion. That lends undeserved credence to the wrongheaded dissenting opinions, and particularly Justice Thomas’s, which is the best of them, but leaves the most important questions totally unaddressed. In short, all the opinions are sloppy or beside the point, and while the result is good, these flaws in the reasoning bode ill for the future.
The problem comes at the confluence of the Due Process of Law and Equal Protection Clauses. Due Process of Law forbids the government from taking away your life, liberty, or property for arbitrary reasons or in arbitrary ways. So, for example, the government can’t take away your stuff or throw you in jail on a “because I say so” basis. Equal Protection, on the other hand, says the government cannot discriminate against you—it can’t treat you differently from other people, without some good reason. The two things do, indeed, tend to overlap: for you to be discriminated against for no good reason (Equal Protection) is a kind of arbitrary treatment (Due Process of Law). But they are not always the same thing. The government can take certain things away from you without violating Due Process of Law, because you had no right to those things; yet that same deprivation might violate Equal Protection because it is taking those things away on a discriminatory basis.