The Department of Justice recently released a series of decades-old legal opinions, drafted by the Office of Legal Counsel (OLC), to support its recent assertion that former White House Counsel Don McGahn is immune from congressional subpoena. Whether senior presidential aides must comply with congressional subpoenas is obviously an important legal question, and it’s good that the public now has access to some of the OLC opinions that grapple with it. But the ad hoc release of these opinions raises more fundamental questions about the role of the OLC and the public’s right to know how the executive branch interprets the law.

Although the OLC is a relatively obscure office, it has a singular role within government: to decide what the law means, at least as far as the executive branch is concerned. Exercising that power, it has answered thousands of important legal questions within government—about the scope of executive power, the constitutionality of surreptitious surveillance, the lawfulness of covert operations, and much more.

The OLC has been described as the “Supreme Court of the Executive Branch” because its opinions bind federal officials on legal questions that rarely, if ever, make their way before a court. While the OLC’s opinions are generally kept secret, they’re occasionally released, giving us a glimpse into the world of secret law they’ve created.

The Bush administration relied on OLC opinions to justify its torture of detainees. The Obama administration relied on OLC opinions to justify its drone strike of a U.S. citizen in Yemen. And now the Trump administration is relying on OLC opinions to justify its refusal to comply with subpoenas issued by the House of Representatives in its impeachment inquiry.

Although its opinions resolve enormously consequential and often constitutional questions about the limits of the government’s power, the OLC has refused the many demands made over the years for it to systematically make its opinions public. Instead, the OLC has published its opinions selectively, leaving the public with a piecemeal understanding of the important role it plays within government, and of the legal interpretations it has imposed upon it.

The rationale that the OLC has offered in defense of its excessive secrecy is not persuasive.

In an ongoing lawsuit by the Campaign for Accountability (represented by the Knight First Amendment Institute at Columbia University, where I work), the OLC has argued that its legal opinions are merely advisory, and that publishing them would expose, and thereby chill, government deliberations.

Generally speaking, neither of these things is true. For over 200 years, federal officials have treated opinions issued by the OLC (and its predecessors) as binding. This includes Robert Mueller, who, as special counsel, felt bound by the OLC’s conclusion in 2000 that it would be unconstitutional to indict or prosecute a sitting president. The history shows that these opinions are not advisory; they’re binding, unless superseded by a later OLC opinion or displaced by a federal court ruling on point. In their effect on the executive branch, they’re nearly indistinguishable from federal court rulings, which are also binding unless superseded by a later opinion or displaced by a higher court ruling.

It is also not quite accurate to say that publishing the OLC’s opinions would reveal government deliberations. Quite often, the OLC’s opinions put the finishing legal touches on policy decisions already made, as when the Department of Homeland Security sought OLC assurance that the Deferred Action for Childhood Arrivals program—known as “DACA”—was lawful. Other times, the OLC’s opinions are sought when a policy dispute between two agencies turns on a legal dispute, as when the U.S. Postal Service and the Office of Personnel Management disagreed about whether postal employees were entitled to retirement credit for the period of time that the Postal Service had defaulted on its retirement contributions.

To be sure, sometimes the OLC says “no,” and publishing those opinions might disclose policies considered but never implemented. Even in that circumstance, however, the OLC’s opinions serve as crucial precedent that binds the government and that shapes the OLC’s own future opinions. It is also apparently common for the OLC to alert a requesting official when the agency intends to say “no,” to give the official a chance to rescind the request.

For decades, then, the government has relied on the OLC as a secret Supreme Court, to settle legal disputes and decide important questions about executive power and individual rights. It is not enough for the OLC to release these opinions selectively. In a democracy, the public must be able to judge for itself, and in the light of day, the legal rules that shape our government.