President Donald Trump tweeted that a civil war could be the result of his impeachment. According to a report by the New Yorker, he later added that his "very serious foot injury" would prevent him from fighting in that theoretical civil war.  Trump had five deferments from service in Vietnam, four were for education, and the fifth was a medical deferment, for a foot condition he described as heel spurs. We asked podiatric surgeon Dr. Jacqueline Sutera (who has not treated Mr. Trump) to explain the diagnosis.