The words from one president to another, somewhat casual in tone, were not casual at all in meaning: “I would like you to do us a favor, though.” Those words have now prompted deployment of the ultimate political weapon, an impeachment process enshrined in the Constitution as a means other than the ballot to remove a president from office. When history writes the story, the seemingly innocent request from President Donald Trump to his Ukrainian counterpart will show their infamous July 25 phone call had a lot behind it, at least implicitly. It had the weight of U.S. military power...