The congressional impeachment inquiry into US president Donald Trump’s Ukraine dealings, and his administration’s claims of executive privilege—that oft-cited excuse to withhold information from investigators and the public—put Americans in uncharted legal territory.

Executive privilege isn’t written into the Constitution, however, the Supreme Court has held that such a privilege stems from the president’s constitutionally-derived powers and duties. Yet the limits of this vague privilege have never been tested in the context of a court case about a congressional impeachment inquiry of a president.

Trump, his lawyers, and executive agency officials all claim that information about the administration’s Ukraine dealings isn’t subject to review because it’s shielded by a blanket protection. But there is no precedent to support their claims. Much remains unknown about the limits of executive privilege, and what is known indicates that Trump’s view of his own right to privacy as absolute is unfounded.

Executive privilege allows the president and high-level executive branch officials to keep certain communications private if disclosure would disrupt official functions or jeopardize national security. Still, the protection isn’t unlimited. The sole Supreme Court case to consider presidential privilege arose under different circumstances, but indicates the president’s view of this protection is too expansive.

US v. Nixon, 1974

In 1974, the Supreme Court decided US v. Nixon, a matter arising from a special prosecutor’s criminal grand jury investigation of president Richard Nixon’s White House aides, the ones involved in the Watergate break-ins. The prosector subpoenaed audio tapes of conversations recorded by Nixon in the White House. The president refused to turn them over, claiming executive privilege. But the high court strongly disagreed with the president, and its decision effectively ended his presidency, prompting him to quit before a formal impeachment trial in the Senate.

The justices held that presidential privilege does not extend to information that’s germane to criminal investigations.

Their unanimous 8-0 ruling wasn’t all bad news for presidents, though. It found “constitutional underpinnings“ for executive privilege, though it isn’t mentioned in the Constitution. “Whatever the nature of the privilege of confidentiality of Presidential communications in the exercise of Article II powers, the privilege can be said to derive from the supremacy of each branch within its own assigned area of constitutional duties,” the court wrote.

Still, it can’t be an absolute privilege because if it was, the court explained, it would conflict with the judiciary’s work. The judicial branch needs information to do its job, which is seeking justice in criminal prosecutions. It’s impossible for the president’s work to necessarily trump the needs of those in equal branches of government, so conflicts must be resolved in “a manner that preserves the essential functions of each branch.”

The Trump impeachment inquiry—a congressional investigation rather than a criminal prosecution— presents different facts from Nixon’s case. But the 1974 ruling indicates that if a legislative branch’s request for information is pitted against executive privilege, courts will consider their competing interests in fulfilling their constitutional duties.

And if the past is an indication, then it’s not clear that the president’s need for privacy trumps representatives’ interests in accessing information for their investigation.

The Nixon court held that “historic commitment to rule of law” outweighs a president’s generalized need for privacy. Congress is constitutionally tasked with investigating alleged wrongdoing and voting on articles of impeachment for a president, when appropriate. Thus, the interest of investigators in uncovering the truth would be weighed against the president’s interest in keeping communications private if subpoena challenges do end up in court.

The justices in 1974 also ruled that presidential privilege “is limited to communications in performance of (a President’s) responsibilities … of his office,” made while shaping policies and decisions. But Trump is accused of using his presidential powers to shape policies that advance his own personal interests, so the information he wants shielded might not ultimately be deemed protected by executive privilege.

Since the 1970s

Executive privilege cases have come up in lower courts since the 1970s. Though none have to do with a presidential impeachment inquiry, there are a few DC circuit court decisions that shed light on the protection, explained University of Texas School of Law professor Steve Vladeck in SCOTUSBlog.

These cases show that executive privilege can apply to communications that don’t involve the president if related to “official government matters” calling for his “direct decision-making.” Still, protection can only be claimed by senior White House advisers and their immediate staffers, and the scope of the privilege is to be construed “narrowly.”

A 2008 case, House Committee on the Judiciary v. Miers, is especially relevant when considering Trump administration claims, Vladeck notes. The judge held that senior advisers to the president—past or present—could not use executive privilege to shirk valid congressional subpoenas.

Congress’s power of inquiry “lies at the very heart” of its constitutional role, the judge wrote. Using US v. Nixon, the court concluded that congressional subpoena power involves an equal Congress performing its duties alongside the executive branch, just as Nixon’s case involved a clash between two equal government branches. As such, executive privilege couldn’t just trump congressional inquiry powers as an absolute.

It seems, based on the prior rulings, that a clash with Congress won’t necessarily be resolved in favor of the president in court. “Much remains unanswered by the courts, but the guidance from [these cases] should go a long way toward separating colorable privilege claims from those that are patently meritless,” Vladeck writes.

Sounds familiar

If talk of executive privilege sounds familiar, yet incomprehensible, it’s because you’ve heard the claim of blanket protection from the Trump administration before, and it was no more evident then that the president is entitled to such extensive protection.

In May, the president claimed executive privilege shielded all the underlying materials in special prosecutor Robert Mueller’s report on Russian interference in the 2016 US elections and alleged obstruction of justice by Trump. Some legal analysts suggested then that claiming privilege was just a stalling tactic: Trump wants cases to play out in court as the 2020 elections approach because he thinks he’ll win and will shut down Democratic opposition, preventing any further inquiries into the matter.

Assistant Tennessee solicitor general Jonathan Shaub explained in Lawfare that “over the past 40 years, the executive branch has been steadily developing a comprehensive, and largely consistent, doctrine of presidential control over information—one that has never been tested by an appellate court.”

Shaub argued that Trump has been taking an even more expansive approach by making “protective assertions.” Essentially, the president asserts a blanket privilege, reserving the right to withhold all information as a preliminary step before officially claiming privilege and facing the balancing of interests test used by the Supreme Court in 1974. Shaub says the administration is carving a new kind of protection out for presidents, one that’s unconstitutional when pitted against the needs of an equal branch of government.

Unprecedented

No one really knows the precise limits of executive privilege in this situation. While past cases indicate it isn’t as simple or expansive as the Trump administration claims, the best case scenario is perhaps for his privilege assertions to never be tested in court at all and for us to keep not having the answers because it would show the government branches are operating properly, which is to say, cooperating.

Most disputes over information exchanges between the legislative and executive branches are resolved with negotiations, not litigation, according to a 2014 Congressional Research Service report on executive privilege. Ideally then, the government branches would resolve the disputes as is customary, negotiating a mutually satisfactory conclusion, like leaders, instead of warring in the courts.