Good thing Republicans picked up a couple of seats in the midterms — and that Harry Reid and Chuck Schumer torched the filibuster on presidential appointments. Otherwise, the appointment of William Barr to replace Jeff Sessions might have faced real trouble after his memo to Rod Rosenstein emerged this morning. In an unsolicited professional opinion, Barr blasted Robert Mueller’s special-counsel probe into potential obstruction as “grossly irresponsible,” and predicted it would create “disastrous implications.”

Democrats will argue that the memo has disturbing implications of its own:

William P. Barr, who has been nominated to become the next attorney general, wrote a memo to Justice Department leaders earlier this year criticizing special counsel Robert S. Mueller III for a “fatally misconceived” legal theory of how President Trump may have obstructed justice.

The memo, written in June and addressed to Deputy Attorney General Rod J. Rosenstein, is likely to raise alarms among Democrats who have sought to protect the Mueller investigation. And it could intensify the partisan fights surrounding Barr when he comes before the Senate Judiciary Committee for confirmation next year. …

The memo argued that a president can be investigated for acts that would directly alter an investigation, such as suborning perjury or destroying evidence. But Barr contended that the department should not investigate the president for acts that are allowed under his legal authority as president but could, in theory, be done for the purpose of blocking an investigation.

Specifically, Barr wrote that because a president has the power to hire and fire an FBI director, Mueller should not investigate the president’s decision to fire Comey. He wrote that doing so would ultimately limit the chief executive’s authority over government agencies, and the authority of senior Justice Department officials who might later decide to shut down investigations or not approve the filing of charges.

“Mueller should not be permitted to demand that the president submit to interrogation about alleged obstruction,” Barr wrote. “Apart from whether Mueller [has] a strong enough factual basis for doing so, Mueller’s obstruction theory is fatally misconceived.”

Where one stands on this effort largely depends on where one stands on Mueller. The Washington Post’s Aaron Blake writes an I-told-you-so in declaring Barr’s memo proof of his status as “an anti-Mueller zealot”:

But the new memo takes things to a whole new level. The quotes described above were offered to reporters who inquired about various matters. Some of them are problematic if you’re concerned about the future of Mueller’s probe, but to this point he had never explicitly suggested Mueller’s probe was illegitimate. He just minimized it relative to the Clintons and seemed to prejudge one specific event. The Comey firing, after all, is now just one of many potentially significant events in the obstruction probe.

The memo was extremely detailed and — perhaps most importantly — unsolicited. Here was a man who went to the trouble of rhetorically dismantling one entire half of Mueller’s probe, of his own volition. And the language used is not muted. “Grossly irresponsible,” “fatally misconceived,” and “potentially disastrous implications” are the words of someone who feels strongly that this is a miscarriage of justice. They are the words of a zealot who would seem to do whatever was in his power to hamstring that portion of Mueller’s probe. After all Barr, in his own estimation, would be preventing a disaster for American government. Barr isn’t just saying Trump is innocent; he’s saying the entire underpinning of the investigation is wrong and perhaps illegal.

Aha! Senate Democrats will exclaim. This is the smoking gun that proves Trump appointed Barr to be the hatchet man on Mueller! It might not be just Democrats making that case, either. Jeff Flake just got blocked a third time from advancing his bill to protect Mueller, a bill that had originally gotten support from fellow Republicans Chuck Grassley and Thom Tillis. At the very least, Flake may join them in opposing Barr, as might Bob Corker, both of whom are opposed to Trump himself on a number of issues.

But just how much of a smoking gun is this? For the defense, Andrew C. McCarthy concludes that it’s nothing of the sort — only an excellent legal review of the circumstances. Not only are Barr’s viewpoints correct, McCarthy argues, but also necessary to rein in Mueller’s seemingly limitless investigation:

It is exactly what we need and should want in an attorney general of the United States: the ability to reason through complex legal questions in a rigorously academic way. Not to bloviate from the cheap seats, but to think these issues through the way a properly functioning Justice Department does: considering them against jurisprudence, statutes, rules, regulations, and Office of Legal Counsel (OLC) opinions, with a healthy respect for facts that we do not know or about which we could be wrong — facts that could alter the analysis.

That is precisely what Bill Barr did in June, when he penned an unsolicited memorandum to top Justice Department officials on a matter of immense national significance: the obstruction aspect of Special Counsel Robert Mueller’s investigation of President Trump. …

Barr wrote not as an advocate representing someone in the investigation, but as a former high-ranking government official concerned about the institutions of the executive branch, particularly the Justice Department. Special Counsel Mueller’s apparent obstruction theory may have been conceived with the specific facts of President Trump’s situation in mind — Trump’s expression of hope that the FBI would drop any investigation of Michael Flynn, his decision to fire FBI director James Comey. But while a prosecutor may believe his application of a legal principle is narrow, once that application becomes a precedent, only the limits of logic curtail its further, potentially paralyzing extension.

As Barr elaborates, if a president may be prosecuted for obstruction based on carrying out the executive’s constitutional prerogatives — exercises of prosecutorial discretion, giving direction to the course of an investigation, making personnel and management decisions — then every other official in the Justice Department is similarly vulnerable. The apprehension that proper and necessary acts could be construed as improperly motivated, and therefore as actionable obstruction, would profoundly undermine the administration of justice.

This is not an entirely academic argument. We saw something similar to this in Texas, when an overzealous and politically motivated prosecutor charged then-Governor Rick Perry with a crime for having issued a veto. The indictment undermined Perry’s presidential aspirations in 2015 but ended up as a short-lived footnote anyway. A federal court slapped down the Travis County DA over First Amendment grounds, and not long afterward so did a Texas court of appeals judge. Without a corrupt cause established, the legal exercise of proper authority by a public official is not a crime regardless of what its impact might be.

But was there a corrupt cause in Comey’s firing? The extension of the investigation post-Comey would indicate no, and Barr’s point about a high bar on such questions remains. Without demonstrable and incontrovertible evidence of corruption, assigning a special prosecutor to probe any unpopular executive decision not only risks paralysis in the executive branch, it criminalizes politics. There had already been sufficient reason to cashier Comey, as Rod Rosenstein himself had argued in an earlier memo, and elected officials from both parties had called for Comey’s head (for different reasons) over his handling of the probe into Hillary Clinton. There are so many rational reasons to fire Comey that turning it into an obstruction probe defies common sense — or so Barr argues.

As Attorney General, Barr would get to decide these questions when Mueller turns in his report. He would become the supervisor, taking over for Rosenstein, who apparently didn’t take Barr’s advice over the summer. That doesn’t mean that Barr would fire Mueller, but he could decide to lock up any section of Mueller’s report that deals with obstruction as irrelevant. That would leave only the Russia-collusion material, which at this date looks pretty thin — so far, anyway. That would be the most certain method of keeping Mueller in check, far more so than firing him, which would free Mueller to go directly to Congress.

Democrats will make Barr a top target to prevent this, but it’s almost certainly a losing battle. Trump’s biggest GOP opponents are leaving — Flake and Corker especially — and Republicans have two more votes to get Barr past the finish line. Even if Susan Collins and Lisa Murkowski balk, Mitch McConnell would still have 51 others, plus Mike Pence in reserve. It’ll be yet another victory for, er … [checks history] … Harry Reid. And Chuck Schumer, and Dick Durbin, and Dianne Feinstein, and every other Senate Democrat who thought the 2013 nuclear option on the filibuster was a splendid idea.

Barr warned Trump this would come up as an issue in his confirmation, according to CNN. Whether Trump saw that as a bug or a feature will be the core of the debate over Barr’s nomination from now until his confirmation, of course. Don’t expect Trump to take Senate Intel ranking Democrat Mark Warner’s advice in the second clip, either.

William Barr, President Trump's pick for attorney general, discussed memo criticizing Mueller probe with Trump and told him it would likely come up during his Senate confirmation, source tells @LauraAJarrett. https://t.co/fuuCmRkzx4 pic.twitter.com/ogIIsfPvSt

— CNN Newsroom (@CNNnewsroom) December 20, 2018

Mark Warner, top Dem on Senate Intel, tells me that Trump should withdraw William Barr's nomination as attorney general after memo surfaced showing his concerns about Mueller probe. Warner also criticizes Whitaker move not recuse. And he discusses Senate Intel work w/Mueller team pic.twitter.com/5FAsgU13lX

— Manu Raju (@mkraju) December 20, 2018