Twitter was incensed Saturday after Donald Trump used Barbara Bush’s funeral as an opportunity to tout his private business in a tweet, dubbing his Mar-a-Lago golf resort the “Southern White House.” Trump noted that he would be watching Bush’s funeral — on TV — at his golf resort. The latest “southern” title of Trump’s private “White House” was particularly galling to many who called it a “dog whistle” to racists. Trump used to refer to Mar-a-Lago as the “Winter White House.” The “Southern White House” was where Confederate president Jefferson Davis lived during the Civil War. Angry tweets also pointed...