People have carelessly handled classified info since they started classifying info. Whether they were folders left on restaurant tables, car seats, unlocked briefcases, whatever. So there’s ample precedent for not prosecuting. You simply can’t go from careless breach of handling to willful violation of the law. So Clinton got the wrist slap she deserved, and the Republicans can probably still keep milking this anyway and fold it neatly into their perpetual persecution pipeline.