1) The notion of helping people to die is contrary to the core of medicine.
In Oregon, only a handful of physicians have written lethal prescriptions over the past 10 years, and only about 1 death in a thousand happens this way. The overwhelming majority of physicians and terminally ill patients essentially vote against PAS.
2) We should not take the step of making medical care merely another commodity for which there is a supply and a demand — i.e., whatever (legal thing) the patient wants, the patient gets.
Think about patient "rights" to receive antibiotics any time they wish; pain killers dispensed on demand; teen boys able to demand steroid hormones for body building. Someone might question why the doctor gets to impose his or her views on these people if they’re willing to take the risks, but physicians need to be able to operate within a code of ethics and without the expectation that "what a patient wants, the patient gets." This will lead to the Kevorkian ethical standard becoming the norm.
3) The Oregon law has seen a lot of abuse, despite what the newspapers editorialize.
None of the Oregon assisted suicide patients last year were referred for evaluation for depression: it would be nearly a statistical impossibility for none of the terminally ill patients to have been depressed. In fact a recent study at OHSU suggests that 20-25% were clinically depressed. But no one is looking over the shoulders of the assisted-suicide activists as they arrange for lethal prescriptions. The Oregon Public Health Division has zero resources for it.
4) Accepting this will start us down the road to worse abuses.
This isn’t speculation — it’s already happened. In Oregon, at least one patient was injected with lethal medication despite the fact that the law prohibits it. Another elderly woman, somewhat demented, was pressured by her daughter to get a lethal prescription — doctors’ notes say that the woman herself didn’t really seem to want it. In Europe, euthanasia is already becoming commonplace. A Princeton professor has written about a "duty to die" for people whom society finds no longer useful.