Yet as bad as this situation is, the reason Mattis should step down is that he has shilled for the President’s abuse of active-duty military forces for a political purpose. It would have been bad enough had Trump called in all National Guard forces, which have traditionally had at least some role in meeting contingencies here at home; the bulk of the forces sent to the border were active-duty forces. Such forces should be used to defend the country from legitimate security threats, not used to score points with a president’s political base before an election, especially when civilian authorities could handle any such “problem” (if it were legitimate) easily.