What the OR law allows is not the voluntary taking of one's own life, it allows murder by a physician using a specific method of killing. If a suicidal old person in OR asks you to smother him with a pillow you will be prosecuted for murder if you grant his request. But if you have "MD" after your name and give him a drug which will kill him you won't be prosecuted for anything. What's the difference? On a moral level it's still murder whether the OR law prohibits it or not.
I suppose another way to look at the issue is this, if the American people want to continue to legalize the murder of pre-birth babies, which apparently they do, they may as well legalize the murder of old sick people as well. I just wonder how long it will be before any type of "undesirable" or unwanted human being can be legally murdered in America the way they were in Nazi Germany.
Whether we like it or not, barring a constitutional amendment specifically adressing the issue, the states have the right to their own abortion laws, as well as their own assisted suicide laws.
You obviously have never read the Oregon law, nor the many articles that have come out today. It does not legalize euthanasia--it's suicide that's legalized, and the assistance by a physician. The physician will be prosecuted if he administers the medications.