WASHINGTON — When it comes to presidential obstruction, at least Watergate started with a crime. A stupid crime, but a crime. After 675 days, more than 2,800 subpoenas, nearly 500 search warrants, $30 million spent, endless jaw-jaw on cable and countless whiny Trump tweets, we have come down to one fundamental truth. And it’s the same truth that has been terrorizing us all along: Donald Trump’s dirtbag machinations are driven by insane vanity. The First Narcissist’s all-consuming blend of braggadocio and insecurity has turned Washington and its rickety institutions into a dystopian outpost of his id. President Trump obstructed on...