President Donald Trump practically picked one of his defense lawyers to supervise Robert Mueller.

That’s what to make of The Wall Street Journal’s report late Thursday night that Attorney General nominee William Barr secretly lobbied the Justice Department to interfere with the special counsel’s investigation into Trump’s firing of FBI Director Jim Comey. Barr’s arguments are remarkably similar to those Trump’s defense counsel made to Mueller’s office months earlier. And in one important aspect he goes further, arguing Mueller’s conduct amounts to grounds for firing.

Barr has spoken approvingly of Trump’s efforts to interfere with Justice Department law-enforcement decisions before.

He was the only one of 10 former attorneys general contacted by The New York Times who defended Trump’s pressuring of Jeff Sessions to successfully reopen an investigation into unsubstantiated claims that Hillary Clinton culpably assisted a Russian company in buying a company that owns U.S. uranium mines.

Barr also supported Trump’s criticism of Mueller, a lifelong Republican, for hiring some prosecutors who had made contributions to Democratic candidates, despite the apparent absence of a violation of any Justice Department policies or practices. (Barr and his wife, combined, have given more than $750,000 to Republicans over the past 20 years.)

Most of all, days after Trump fired Comey in May 2017, Barr publicly defended the decision, stating that he accepted Trump’s claim that he fired the director because he treated Hillary Clinton unfairly in the email investigation. Barr appeared remarkably unconcerned that Trump might have actually fired Comey because of his investigation of the Trump campaign’s possible coordination with Russia’s interference in the 2016 presidential election, as the president later squarely admitted was actually the case.

“ Barr’s memo reportedly goes so far as to suggest that any effort by Mueller to pursue an investigation of Trump’s firing of the FBI director would amount to misconduct. ”

The Journal reveals that Barr went beyond his vocal public defense of Trump’s firing of Comey, and also took it upon himself to draft a 20-page memorandum on the topic for Deputy Attorney General Rod Rosenstein, Mueller’s DOJ supervisor. Barr’s memo decries any effort by Mueller to investigate the president for potential obstruction of justice based upon the Comey firing.

Barr’s memo is apparently grounded on the same sweeping view of unencumbered presidential power he championed when serving as President George H.W. Bush’s attorney general. Barr’s memo reportedly argues that the DOJ should bar Mueller from even attempting to question the president regarding his reasons for firing Comey, asserting that permitting such an interrogation “opens the door for every decision that is alleged to be improperly motivated to be investigated as ‘potential criminal obstruction.’”

Barr’s memo reportedly goes so far as to suggest that any effort by Mueller to pursue an investigation of Trump’s firing of the FBI director would amount to misconduct, characterizing such a probe as “grossly irresponsible” with “potentially disastrous implications” for the Executive Branch. This makes the prospect of Trump installing Barr as the attorney general gravely disturbing and indeed a palpable threat to the Mueller investigation.

Barr’s arguments appear remarkably similar to those Trump’s defense counsel made in a 20-page memorandum they submitted to the Mueller’s office in January 2018, which was later leaked to The New York Times. Trump’s lawyers similarly argued that, because the president’s firing of Comey was a “lawful exercise of his constitutional power,” it “cannot constitute obstruction of justice,” regardless of whether the firing actually obstructed an ongoing investigation.

The similarity between the Trump and Barr memoranda is all the more striking in light of a report that, for a period of months, ending only early this year, the president and his advisers sought to engage Barr to join the Trump defense team. While Barr reportedly demurred, the question arises whether Barr shared his views with Trump’s counsel.

Given that Barr appears to consider Mueller’s very conduct of his investigation of the Comey firing to constitute serious impropriety, it is more than possible that an Attorney General Barr would order Mueller to limit his investigation, and would fire Mueller if he refused.

Under these circumstances, the Senate has only one viable option if it wishes to allow Mueller to complete his investigation unimpeded: Demand that Barr agree to fully recuse himself from the Mueller investigation, and leave supervision of the probe in the hands of Rosenstein, who apparently (and wholly properly) rejected Barr’s prior call for him to interfere with the special counsel’s work. If Barr refuses to make such a commitment, he should not be confirmed.