There is no doubt that Trump deserves to be prosecuted. But we cannot afford to do that. We must observe the fiction that we do not elect people who need to be prosecuted. If we do elect such awful people, then what good is our system? Prosecuting a former president is a self-proving admission that we cannot govern ourselves, because once we start prosecuting former presidents, we will never stop. (Because, truth be told, we cannot govern ourselves).
Trump's escape should remind us how important our vote is. I recognize the counter-argument that Presidential impunity attracts scoundrels, but I believe the argument is outweighed by the probability that "Lock her up" will become more than something idiots chant at rallies. As one tycoon is said to have said, the trick to great wealth is to put all your eggs in one basket and then watch that basket very carefully. The presidency is our national basket. We need to be very careful about to whom we entrust it, because punishment will not unbreak the eggs.