By TOMMY BEVERIDGE Thought experiment. What if the United States had a vast network of primary care-oriented non-profit health clinics?  Imagine if there were, say, 17,000 locations in the most needed corners of our country? What if these clinics had to see everyone, had to offer a sliding fee scale for their services, and be run by boards comprised of a patient majority?  Just for fun, what if they also provided dental and behavioral health services, worked with local social programs, and helped coordinate with specialists and hospitals? Couldn’t that be a solid cornerstone for primar...