This week, Daniel Howes says Detroit’s automakers are using investment decisions in a union contract year to politick President Donald Trump. The reason: General Motors Co.’s plans to close four U.S. plants as part of a restructuring moved the president to repeatedly lambaste the automaker on Twitter and in public appearances. In the forming battle for the hearts and minds of the work-a-day Midwest, Detroit's automakers are proxies personally selected by POTUS. And Michigan and Ohio are the principal battlegrounds.