I know (from working in heath care) much of the anxiety that leads people to support these laws is fear: fear of intractable pain, fear of loss of function and/or faculties, fear of becoming a burden to family and fear of seemingly unending suffering. None of these fears are unreasonable and many of them have stemmed from past failures of the health care system such as denying adequate pain relief to those dying of cancer in the fear they might become addicted. (Yes, that was common)  

Many of these fears can be addressed and treated with proper medication, support and conversations with family members and members of the health care system.  Our society does not deal well with illness, suffering and death. If we focus on education, supportive interventions and listening carefully, most, if not all of a patient's concerns can be adequately addressed and one can face serious illness and impending death with dignity, care, compassion and minimal pain.