To wit:
“The attorney-client privilege is the oldest privilege recognized by Anglo-American jurisprudence. In fact, the principles of the testimonial privilege may be traced all the way back to the Roman Republic, and its use was firmly established in English law as early as the reign of Elizabeth I in the 16th century. Grounded in the concept of honor, the privilege worked to bar any testimony by the attorney against the client”
Which is exactly what is happening here.
It’s a historic rebellion against the Law of the United States.
The prosecutors claimed that the communications between Trump and Corcoran were in furtherance of a crime. You can argue about whether or not that was the case here, but that is a valid exception to the attorney-client privilege.