The "right to life" is retained by the people, not the State, since it is individuals who have lives. You would have a better claim that States not allowing physician assisted suicide are violating the Constitution.
Constitutionally, the federal government lacks a general police power. Because of this, the federal government doesn't even have jurisdiction over actions universally recognized as crimes such as murder or rape, and there certainly is no right to commit those things.
Furthermore, rights are not violated when an individual gives consent.
If you enter a person's house without their consent, the crime is trespassing.
If you have sex with another person without their consent, the crime is rape.
If you take another's property without their consent, the crime is theft.
If you kill another person without their consent, the crime is murder.
A person most certainly retains rights against trespass, theft, rape and murder, however once consent is given, the right is not violated.
Ironically, in the name of rights, the state is depriving a person of their right, the right to consent.
My take on the purpose of the article is to show that even the most esteemed conservatives can sound like liberals where states rights are concerned, so long as the central government is doing something they happen to like.
I don't have my copy of The Constitution at hand right now, but I don't believe it "guarantees" any such right. The DoI enumerates it as one of the "unalienable" rights, but guarantees nothing. The Constitution is supposed to be a listing of the limits constraining government.