Again and again, we hear that the country has too few doctors, particularly for primary care. And Obamacare is supposed to make the shortage much worse in the coming years as more Americans become insured and try to shoehorn themselves into already crowded medical offices. But why, exactly, are doctors in such short supply? I had always assumed the culprit was medical school enrollment. But when I looked into those numbers, I found that they are actually increasing noticeably. Thanks to the opening of new medical schools and expanded admissions at existing ones, enrollment is projected to rise by 30 percent between 2002 and 2017, according to the Association of American Medical Colleges.