Paul Farmer — American Educator born on October 26, 1959,

Paul Edward Farmer is an American anthropologist and physician who is best known for his humanitarian work providing suitable health care to rural and under-resourced areas in developing countries, beginning in Haiti. Co-founder of an international social justice and health organization, Partners In Health, he is known as "the man who would cure the world," as described in the book, Mountains Beyond Mountains by Tracy Kidder... (wikipedia)

But as for activism, my parents did what they could, given the constraints, but were never involved in the causes I think of when I think of activists.
For me, an area of moral clarity is: you're in front of someone who's suffering and you have the tools at your disposal to alleviate that suffering or even eradicate it, and you act.
What the American public thinks is very important to the future of global health. Many people are moved by the idea that there is unnecessary suffering in the world, and we could do a lot to stop it. We have the technologies necessary to stop most of the suffering.
So I can't show you how, exactly, health care is a basic human right. But what I can argue is that no one should have to die of a disease that is treatable.
But if you're asking my opinion, I would argue that a social justice approach should be central to medicine and utilized to be central to public health. This could be very simple: the well should take care of the sick.