For all the time he’s spent investigating him, Rep. Elijah Cummings still doesn’t quite get President Donald Trump. It’s not just that he avoided naming names when, at a speech Wednesday at the National Press Club, he called for an end to racist rhetoric in our politics. No, it’s his idea to invite the president to visit his congressional district in the wake of Mr. Trump’s attacks on him and Baltimore. Mr. Cummings said he would like to show the president the great diversity of his district, from communities with real and profound needs to those that are home to “the richest of the rich,” and perhaps convince him that his description of it as “rodent and rat infested” and a place where no one would want to live was unfair. Maybe even get him to commit the federal government to providing more funds for drug treatment, community building and other vital causes.