It's an awful law, and physicians should have no part in helping someone to kill themselves.
That said, I do not see where in the Constitution the federal government derives authority to overturn this law. I suspect, though, that this was an outcome-based decision on both sides. The Supreme Court is pretty much a political body these days...kind of a Super-Senate. I'll have to read the decision and dissent to see for sure.
The proper thing to do is to get the voters to undo this mess. They're the ones who voted it in. Personally, I voted against it, as it was and is an awful idea.
Does the Oregon law allow Doctors who, who moral or religious reasons, to refuse to prescribe life-ending medicataion to terminal patients?
We hold these truths to be self-evident:That all men are created equal; that they are endowed by their Creator with certain unalienable rights; that among these are life, liberty, and the pursuit of happiness; that, to secure these rights, governments are instituted among men, deriving their just powers from the consent of the governed; that whenever any form of government becomes destructive of these ends, it is the right of the people to alter or to abolish it, and to institute new government, laying its foundation on such principles, and organizing its powers in such form, as to them shall seem most likely to effect their safety and happiness.
Life is an unalienable right, an endowment of the G-d, the Creator. A just and lawful Government may not declare murder legal, nor suicide.
They didn't try to actually overturn it, as that I guess would be too-blatant an intrusion. They did try to subvert it, prosecuting doctors who were doing something entirely legal according to their state law.