Trump's case: When novel theories become legal principles

Defendant Donald J. Trump and his supporters have assailed the 34-count felony indictment of the former president brought by the Manhattan District Attorney as resting on a flimsy, untested and novel legal theory that converts Trump’s alleged misdemeanors to felonies.

While a jury of President Trump’s peers will decide his fate, assuming the case goes to trial, it turns out that the theory of the...