Last week, Attorney General William P. Barr overruled the Justice Department’s sentencing recommendation for President Trump’s ally Roger Stone, who was convicted of lying to Congress, after the president tweeted that the original recommendation was “horrible” and “very unfair.” Barr also ordered a review of former national security adviser Michael Flynn’s prosecution — which, like Stone’s, was initiated by former special counsel Robert S. Mueller III and conducted by career Justice Department attorneys.

These developments are the latest evidence that Barr’s loyalty to Trump threatens the Justice Department’s independence, and they have shaken the public’s faith in the rule of law. But Barr’s attempts to politicize the Justice Department could have been stopped before they began: during his Senate confirmation. Even then, it was clear that Barr’s radical pro-executive branch worldview was contrary to Congress’s institutional interests and made Barr a dangerous pick for a president who, as Sen. Patrick J. Leahy (D-Vt.) warned, “views the Justice Department as an extension of his political power.”

A little over a year ago, I was serving as a senior counsel on the minority staff of the Senate Judiciary Committee, helping Democrats sound the alarm about Barr’s troubling record. A former head of the Justice Department’s Office of Legal Counsel (an office in which I also later served), Barr had espoused an extreme view of executive power that exalted the presidency to a position of inviolability rather than treating Congress as a coequal branch. This theory, which the Supreme Court has never endorsed, grants the president virtually unchecked authority while seriously hamstringing Congress’s ability to hold the president accountable, including its ability to guard against political interference in law enforcement.

Barr had recently reaffirmed these views as a private citizen when, in June 2018, he sent an unsolicited memo to the deputy attorney general arguing that Mueller could not investigate whether Trump obstructed justice by attempting to thwart the Justice Department’s Russia investigation. In a particularly chilling line, Barr wrote that the president has “illimitable” constitutional powers that preclude investigations like the special counsel’s, because “he alone is the Executive branch.”

At his confirmation hearing, Barr defended this view. He also refused to give senators unqualified assurances that he would prevent political interference in the special counsel’s investigation and the related criminal prosecutions being handled by U.S. attorney’s offices. Barr pledged only that he would not tolerate political interference in “bona fide” law enforcement matters and left that term open to interpretation. After Barr’s hearing, Sen. Dianne Feinstein (D-Calif.) reflected many Democratic senators’ sentiments when she concluded that “the situation in which we find ourselves — and the manner in which Mr. Barr has chosen to interpret the law — leaves too many questions about whether he can be an impartial attorney general.” But the Senate voted to confirm him anyway, largely along party lines.

Since then, Barr has facilitated some of Trump’s most authoritarian instincts. He defended the president’s raid on taxpayer money to pay for a border wall — even though Congress had appropriated that money for military construction, refused the president’s funding request for the wall and passed resolutions to block the president’s action. Barr proclaimed the president had the authority to order the killing of Iranian Maj. Gen. Qasem Soleimani without congressional approval, providing shifting legal justifications for the decision. Barr defied congressional subpoenas and backed the White House’s hard-line position that the president has no obligation to comply with congressional inquiries at all, including impeachment.

Barr has also taken actions aimed at delegitimizing the special counsel’s investigation and undermining its conclusions, in addition to his conduct in the Stone and Flynn cases. Barr misrepresented the Mueller report’s conclusions before its release to Congress and the public in an attempt to skew its reception and blunt its impact. He then opened an investigation into the origins of the Justice Department’s Russia investigation, even though the department’s inspector general was already conducting an independent inquiry, and he later publicly disputed the inspector general’s conclusion that the Russia investigation was justified.

Alexander Hamilton observed that “the true test of a good government is its aptitude and tendency to produce a good administration.” To that end, Hamilton believed that requiring Senate confirmation of Cabinet officials would make the president “both ashamed and afraid to bring forward” nominees “possessing the necessary … pliancy to render them the obsequious instruments of his pleasure” and that the President would be unable “to corrupt or seduce a majority of [the Senate’s] members” to vote for such nominees. The Senate’s role as a “check” on “the appointment of unfit characters” is now more crucial than ever, given the president’s claim of unbounded constitutional authority.

The Senate’s constitutionally assigned responsibility of considering presidential nominees is a bulwark against presidential abuse of power, and Barr’s use of the Justice Department as a political cudgel is a stark reminder of why it must be jealously guarded and zealously effectuated.

Unfortunately, by rubber-stamping Barr’s nomination, a majority of Senators have failed Hamilton’s test, causing deep and possibly irreparable harm to the interests of Congress, the Justice Department and the American people.