This is a nakedly corrupt attempt on the part of the president to discredit and derail an investigation of himself at the expense of a human intelligence source to whose protection the FBI and DOJ are committed. My colleague at Lawfare, Quinta Jurecic, and I fleshed out the history of this saga and warned, “Don’t underestimate this episode. It will have a long tail and big consequences—all of them terrible.”

Those consequences, if you believe the president, may start as soon as today, when the White House “officially” issues his “demand.”

Consider a few facts: President Trump has the constitutional authority to make this demand. The idea that the president doesn’t interfere in law-enforcement investigative matters is one of our deep normative expectations of the modern presidency. But it is not a matter of law. Legally, if the president of the United States wants to direct the specific conduct of investigations, that is his constitutional prerogative. If Trump wants to corruptly direct the conduct of an investigation in order to out an FBI source who was helping our government investigate Russian interference in our electoral processes, well, Article II of the Constitution begins with these terrifying words: “The executive Power shall be vested in a President of the United States of America.”

To paraphrase Justice Scalia, the term “the Executive Power” does not mean some of that power or most of it; it means all of it. That includes the power to tell the Justice Department what to investigate. And while the misuse of that power for corrupt purposes is a gross abuse of power that would warrant the president’s impeachment and removal from office, I have no doubt that he has the raw power to do it—if only because he has the power to fire people who refuse to obey his directives.

The only real restraint on the president—other than his own conscience and political pressures—in dipping down into the FBI and Justice Department and directing investigations for his own personal purposes is the willingness of senior law-enforcement officials to carry out improper orders. This is what led to the Saturday Night Massacre during Watergate. Nobody doubted that Richard Nixon had the authority to order the firing of Archibald Cox. The question was who would actually do it. And both the attorney general and deputy attorney general declined.

I believe that President Trump is going to run into a problem if he really means to order up a politically motivated investigation designed to discredit the Mueller investigation at the expense of a U.S. intelligence source. If we assume, for a moment, that an official order will say what Trump’s tweet promises, I don’t believe Attorney General Jeff Sessions (who is recused, in any event) would carry it out. I also do not believe that Deputy Attorney General Rod Rosenstein would do so. And I’m quite certain that FBI Director Chris Wray would never be able to look an FBI agent in the face again if he allowed an investigation to be opened improperly (the FBI does not open investigations without a genuine reason to believe a crime may have been committed)—particularly not an investigation following political pressure to out an FBI informant who provided information in the context of a counterintelligence investigation that was properly predicated.