The past couple of weeks began a new phase for the Trump administration and, potentially, for the institution of the presidency.

Emboldened by his acquittal in a majority-Republican Senate, President Trump spent the past week firing officials who testified against him in impeachment proceedings — part of a rash of retaliation that my colleague Zack Beauchamp labeled “Trump’s purge.”

Then Trump sent a tweet denouncing the Justice Department’s suggestion that Roger Stone, a Trump ally convicted of making false statements, obstruction, and witness tampering, should receive a stiff sentence of seven to nine years. The Justice Department swiftly changed its recommendation, over the apparent protest of four career prosecutors who withdrew from the case. At least one of these prosecutors appears to have resigned entirely from the DOJ.

Attorney General William Barr, for what it’s worth, claims that “the president has never asked me to do anything in a criminal case.” But Trump credited his attorney general for the swift turnaround in the Stone case.

Congratulations to Attorney General Bill Barr for taking charge of a case that was totally out of control and perhaps should not have even been brought. Evidence now clearly shows that the Mueller Scam was improperly brought & tainted. Even Bob Mueller lied to Congress! — Donald J. Trump (@realDonaldTrump) February 12, 2020

The Justice Department’s swift compliance with Trump’s wishes was widely condemned by DOJ alumni, who spoke of why it is important that the nation’s prosecutorial arm retain a degree of independence from its political leader. As Joyce White Vance, a former United States attorney, wrote in Time, if Trump “can corrupt the criminal justice system for the benefit of his friends, there is no reason he cannot also use it to retaliate against those he views as enemies.”

In this sense, the Justice Department is fundamentally different from other federal agencies. While those agencies can wield tremendous power over federal policy, DOJ is tasked with the awesome power to prosecute crimes — and with it, the power to ruin the lives of a president’s political enemies.

For Barr, however, the idea that the Justice Department would be subservient to the president isn’t simply acceptable; it is a constitutional necessity. (Although Barr has also claimed he would not bring a criminal investigation solely because the president wished to investigate a “political opponent.”)

Last November, Barr spoke to the conservative Federalist Society’s annual lawyers convention. His speech focused on the proper role of the presidency, and on the theory of the “unitary executive.” As Barr described that theory, which he enthusiastically supports, every power exercised by the executive branch “must be exercised under the President’s supervision.”

That no one in the executive branch should be independent of the president, and that such independence is in fact constitutionally illegitimate, is one of the core beliefs pushed by conservative legal groups such as the Federalist Society.

More than three decades ago, in Morrison v. Olson (1988), Justice Antonin Scalia published a lonely dissent articulating this theory of the unitary executive. Though no other justice joined Scalia’s opinion in 1988, the Morrison dissent gained a cult following in subsequent years. That cult now includes some of the most powerful people in the country — including Barr and several current members of the Supreme Court.

Indeed, the Supreme Court will hear a case early next month that could make Scalia’s theory of the unitary executive the law of the land.

If you want to understand Barr’s approach to his job — and his disregard for longstanding norms of prosecutorial independence — you have to understand the theory of the unitary executive. For Barr, eliminating such independence isn’t simply an act of partisan loyalty; it is a constitutional necessity.

The unitary executive, explained

The issues at the heart of Morrison are, in many important ways, similar to the issues underlying Trump’s interference in the Stone prosecution.

Morrison upheld a 1978 law providing for the appointment of an “independent counsel” to investigate — and potentially prosecute — high-level government officials accused of committing a federal crime (the independent counsel law expired in 1999). In this case, an independent counsel was appointed to investigate whether then-Assistant Attorney General Ted Olson lied during a congressional hearing.

The counsel eventually decided not to pursue charges against Olson, and Olson would go on to serve as solicitor general of the United States.

Under the 1978 law upheld in Morrison, the attorney general would conduct a preliminary investigation to determine if there was sufficient reason to appoint an independent counsel, but the actual person appointed to this role was decided by federal judges. Once an independent counsel was appointed, they could be removed by the attorney general, but only “for good cause, physical disability, mental incapacity, or any other condition that substantially impairs the performance of such independent counsel’s duties.”

Thus, the independent counsel enjoyed a great deal of independence from both the president and the president’s appointees. Neither the president nor the attorney general could remove an independent counsel simply because they disapproved of the counsel’s work.

This arrangement, according to Scalia’s lonely dissent, was not allowed.

The Constitution provides that “the executive power shall be vested in a President of the United States of America.” For Scalia, “this does not mean some of the executive power, but all of the executive power.” Thus, because the power to investigate crimes and bring prosecutions is entrusted to the executive branch, there cannot be a federal prosecutor who is not fully accountable either to the president or to some lower official that can be fired at will by the president.

The question of who has the power to fire prosecutors, and for what reason, may seem esoteric, but it’s difficult to exaggerate the passion Scalia’s Morrison dissent inspired among many of the Federalist Society’s leading lights. When future Justice Brett Kavanaugh was asked, in 2016, to name a case that he would like to overrule, Kavanaugh said that he wanted to “put the final nail in” Morrison’s coffin.

Barr, meanwhile, spoke of the unitary executive during his Federalist Society address as if it is the only legitimate way to read the Constitution — and as if anyone who doubts it is acting in bad faith:

One of the more amusing aspects of modern progressive polemic is their breathless attacks on the “unitary executive theory.” They portray this as some new-fangled “theory” to justify Executive power of sweeping scope. In reality, the idea of the unitary executive does not go so much to the breadth of Presidential power. Rather, the idea is that, whatever the Executive powers may be, they must be exercised under the President’s supervision. This is not “new,” and it is not a “theory.” It is a description of what the Framers unquestionably did in Article II of the Constitution.

But the case against the unitary executive is not “some new-fangled ‘theory’” either, and it is not an attack that can only be found in “modern progressive polemic.” Morrison was a 7-1 decision authored by Chief Justice William Rehnquist, who spent many decades as the intellectual leader of the Supreme Court’s conservative wing. As recently as 1988, the theory of the unitary executive was a fringe idea on the nation’s highest court.

The unitary executive’s more recent popularity is a testament to Scalia’s power to shape conservative opinion, and of the power the Federalist Society has to popularize ideas that were once viewed as well outside the legal mainstream. But Barr is simply wrong that the unitary executive theory “unquestionably” describes the framers’ vision.

The truth is that the framers themselves had confused and often contradictory views about what the Constitution requires.

The case against the unitary executive

One other person who appeared to reject the unitary executive theory was James Madison. In a 1789 debate about who should be able to remove the comptroller of the Treasury, Madison suggested that some federal officials “should not hold [their] office at the pleasure of the Executive branch of the government.”

Similarly, Alexander Hamilton suggested in the Federalist Papers that the Senate would need to acquiesce in the president’s decision to remove a senior executive branch official. “The consent of that body would be necessary to displace as well as to appoint,” he wrote in Federalist 77.

The point is not that these statements should be taken as gospel — Hamilton’s claim that the Senate could prevent the president from firing top officials is soundly rejected today, and Hamilton himself later abandoned this view. Rather, the point is that the Constitution is sufficiently unclear about whether certain officials can act independently of the president that two of the founding generation’s leading figures disagreed with Scalia and Barr’s approach.

As Fordham law professor Jed Shugerman explained in a recent article, Scalia’s suggestion that the power to investigate crimes and bring prosecutions is reserved to the executive branch is hard to square with early American history. Indeed, for much of the nation’s history, the power to bring prosecutions wasn’t even limited to the government. As Shugerman writes, “for much of English and American history, most prosecution was not an executive function at all because it was a private enterprise.”

Indeed, prosecutions led by lawyers in private practice were the norm until long after the Constitution was ratified. “The vast majority of American prosecutions were still private through the mid-nineteenth century,” Shugerman explains, “as Allen Steinberg and many other historians have demonstrated.”

Similarly, the Senate’s draft of the Judiciary Act of 1789 gave federal district judges — not the president — the power to appoint federal prosecutors. And the final version of that law allowed many federal law enforcement officers to be removed by the judiciary. Current federal law permits federal district judges to appoint interim US attorneys (though only after a temporary appointee named by the attorney general has served for 120 days).

Federal judges occasionally conducted prosecutions during the early days of the American republic. “The federal judges themselves led what appeared to be prosecutions during the Whiskey Rebellion of 1794,” Shugerman writes, “and initiated prosecutions under the Alien and Sedition Acts by convening and presiding over grand juries.”

In the face of this evidence, there are also profound practical reasons to reject the unitary executive theory. If Scalia and Barr’s theory prevails, for example, the president would gain the power to fire Federal Reserve governors at will. That would enable the president to pressure the Fed to juice up the economy during an election year, potentially ensuring the president’s reelection.

The facts of Morrison also highlight why prosecutorial independence is sometimes desirable. That case involved an investigation into one of the seniormost officials within the Justice Department. A rank-and-file prosecutor would understandably fear the professional consequences of leading such an investigation — for the same reason that I would be reluctant to conduct an investigation into one of Vox Media’s top executives.

Yet, regardless of the arguments against the unitary executive, it is clear that Barr does not buy them. Indeed, he rejects them so soundly that he denies that any other reading of the Constitution is legitimate. He even appears to reject the idea that informal norms should constrain the president’s interference with the Justice Department, even if DOJ remains formally subject to presidential authority.

And that means that if Trump tells him to jump, Barr will answer, “How high?”