The Justice Department headquarters building in Washington in 2013. (J. David Ake/AP)

Erica Newland is a counsel for the nonprofit group Protect Democracy and a former attorney adviser in the Justice Department’s Office of Legal Counsel.

President Trump said Thursday that he will “maybe definitely” declare a national emergency to free up funds for his long-promised wall at the southern border. One reason for the president’s hesitation might be that he is awaiting word from the people who would be asked to give such a declaration the green light: Justice Department lawyers at the Office of Legal Counsel, or OLC, where I worked from August 2016 until I quit in mid-November.

Lawyers at OLC wear many hats, but their most significant role comes in advising the White House on the legality of proposed actions, including executive orders, proclamations and other presidential documents.

Laws that allow the president to issue such orders usually include two elements: a list of conditions that must exist in the world before the president can issue the order and a list of actions that the president can take in light of those conditions. When these orders are written, they typically mirror this structure and likewise feature two core elements: the president’s findings that the relevant conditions exist, and the exercise of the relevant powers, as applied to the crisis of the day.

For example, when Trump issued the initial travel-ban executive order early in his presidency, he first alleged the relevant condition: that permitting “immigrant and nonimmigrant entry into the United States” of any non-U.S. citizen from any of the seven designated nations “would be detrimental to the interests of the United States.” Then, having made these allegations about the state of the world, he announced the action he was going to take in light of that condition: banning entry into the United States of all of these people.

When OLC approves orders such as the travel ban, it goes over the list of planned presidential actions with a fine-toothed comb, making sure that not a hair is out of line. It is this work that gives OLC its reputation as home to some of the federal government’s finest attorneys. But when it comes to the president’s findings about the state of the world, OLC generally defers to the president.

This deference, which is baked into OLC’s culture, proceeds from the assumption that the president is acting consistent with Article II of the Constitution and with his oath of office, both of which require that he “faithfully” execute the laws. That means he has a constitutional duty to act honestly and in the public interest. OLC’s deference is also born of a recognition that its lawyers are not equipped to be sophisticated fact-finders.

But when I was at OLC, I saw again and again how the decision to trust the president failed the office’s attorneys, the Justice Department and the American people. The failure took different forms. Sometimes, we just wouldn’t look that closely at the claims the president was making about the state of the world. When we did look closely, we could give only nudges. For example, if I identified a claim by the president that was provably false, I would ask the White House to supply a fig leaf of supporting evidence. Or if the White House’s justification for taking an action reeked of unconstitutional animus, I would suggest a less pungent framing or better tailoring of the actions described in the order.

I often wondered, though, whether my attempts to remove the most basic inaccuracies from the face of a presidential order meant that I was myself failing to carry out my oath to protect and defend the Constitution. After all, the president had already submitted, through his early drafts or via Twitter, his reasons for issuing a particular order. I sometimes felt that, rather than engaging in professionally responsible advocacy, my OLC colleagues and I were using the law to legitimize lies.

I felt more than a twinge of recognition this month when reading a New Yorker article about Trump and the reality-TV show “The Apprentice.” Jonathan Braun, an editor on “The Apprentice,” described how editors would “reverse engineer” episodes after Trump made impulsive decisions about firing a contestant. The article described editors “scouring hundreds of hours of footage . . . in an attempt to assemble an artificial version of history in which Trump’s shoot-from-the-hip decision made sense.” Like a staff member at “The Apprentice,” I occasionally caught myself fashioning a pretext, building an alibi.

Eventually, I decided that the responsibilities entailed in my oath were incompatible with the expectations of my job. If my former colleagues at OLC, and throughout the Justice Department, are now working on the possible declaration of a national emergency, I dearly hope they are as meticulous in their review of the president’s justifications as they are in their review of the actions he plans to take. And I hope, more than anything else, that they are asking themselves whether they, too, are just fashioning a pretext, building an alibi.