It would be wise these days to write black letter law on privilege in pencil because a slew of cases — all centering on President Trump — are marking the bounds of what is legally protected and what is fair game for prosecutors building cases against the former president. 

The failure of privilege to protect the former president— surfacing in a series of rulings from both district and appellate judges —  is unlocking reams of testimony that could seal Mr. Trump’s fate. 

The latest sealed ruling from a federal district court judge, James Boasberg,  rejects Mr. Trump’s assertion of executive privilege over Vice President Pence’s potential testimony relating to January 6 and partially knocks down Mr. Pence’s own claim that the testimony is protected by the Constitution’s Speech or Debate Clause.  

The decisions from Judge Boasberg was first reported by the New York Times. It is not immediately known how tightly the jurist drew the circumference of Mr. Pence’s privilege, which comes from his constitutional role as president of the Senate, with the taproot of his authority snaking to Article I, not Article II. 

The Times’s Maggie Haberman, who reported Judge Boasberg’s decisions, tweets that Mr. Pence “must testify on any illegal acts committed” by Mr. Trump, meaning that the former vice president will have to testify before a grand jury contemplating criminal charges against the former president. Mr. Pence could be protected from testifying about his own actions certifying electoral results that day because they were constitutionally mandated.     

Mr. Pence has vowed to appeal any ruling that does not accord with the blanket  constitutional protection he asserts was due his office, telling ABC that “we’re going to respect the decisions of the court, and that may take us to the highest court in the land,” meaning the Supreme Court. 

A similar challenge, from Senator Graham in the Fulton County district attorney’s  investigation into criminal election interference in Georgia’s 2020 election, was likewise only partially successful. Mr. Graham testified before a grand jury in that case. 

The Speech or Debate privilege is particularly potent because it is absolute and enumerated in the Constitution, which ordains that lawmakers “shall not be questioned in any other Place” for “any Speech or Debate in either House.” The Supreme Court has ruled this covers solons while they act “in the sphere of legitimate legislative activity.”    

Last week, in another sealed ruling, Judge Beryl Howell, Judge Boasberg’s predecessor as chief of the federal district court, ruled that more than a half-dozen former administration officials could not invoke executive privilege to avoid testifying. The most prominent of these is Mr. Trump’s former chief of staff, Mark Meadows, who had a firsthand seat to the events of January 6.

Joining Speech or Debate protection and executive privilege as shields breached for Mr. Trump is attorney-client privilege, which dates back to the reign of Elizabeth I, the “Virgin Queen,” and is often considered the oldest privilege in the Anglo-American tradition. Judge Howell ruled that it did not cover Mr. Trump’s communications with one of his attorneys, Evan Corcoran.

Mr. Trump failed to muzzle Mr. Corcoran because of the ‘crime-fraud exception,’ which dictates that when the privilege is used to further criminal activity, it evaporates. In Clark v. United States, the Supreme Court explained that  “a client who consults an attorney for advice that will serve him in the commission of a fraud will have no help from the law. He must let the truth be told.”