The sentencing of former (and future) President Donald J. Trump in a Manhattan courtroom on Friday was the culmination of a titanic legal saga that tested, and arguably rent, the legal and political structure of the United States. But while one might have expected that such a struggle would conclude with a roar, it instead ended with a quiet whimper. It didn’t have to be that way. Manhattan District Attorney Alvin Bragg had revived the election…