The story of the Trump campaign’s attack on our elections could have been the story of the Trump administration’s four-year-long attack on our institutions. If, early on, the Justice Department lawyers charged with selling the administration’s lies had emptied the ranks — withholding our talents and reputations and demanding the same of our professional peers — the work of defending President Trump’s policies would have been left to the types of attorneys now representing his campaign. Lawyers like Mr. Giuliani would have had to defend the Muslim ban in court.