There’s one thing we know for sure from Attorney General William Barr’s Sunday letter to Congress outlining the Mueller report: that the special counsel left wide open the question of whether Trump committed obstruction of justice.

“While this report does not conclude that the President committed a crime, it also does not exonerate him,” reads an excerpt from the report that Barr quotes in his letter.

But if the question was left open, who was supposed to answer it? Was it a prosecutorial decision for Barr and Deputy Attorney General Rod Rosenstein? Or a political question for Congress?

Attorneys told TPM that the issue may have been left open for Congress to handle, and that Barr’s involvement through the Sunday letter — skimpy on analysis but heavy on conclusions — could constitute the first volley in a political fight that was meant for Congress.

The question is further complicated by a June 2018 memo that Barr sent to Rosenstein in which he outlined his critique, made as a private citizen, of Mueller’s approach to the issue of obstruction.

It appears from Barr’s Sunday letter that Mueller decided “not to make a traditional prosecutorial judgment,” and instead “leaves unresolved what the Special Counsel views as ‘difficult issues’ of law and fact concerning whether the President’s actions and intent could be viewed as obstruction.”

Former federal prosecutor and Clinton White House staffer Nelson Cunningham told TPM that Mueller punted on the issue in a way that left it open as a political question for Congress to handle, not Barr.

“What Mueller was plainly signaling was that this was a political decision, not a law enforcement decision,” Cunningham said, adding that “for Barr and Rosenstein to view it as a simple law enforcement decision flies in the face” of what the report appears to have suggested.

Gene Rossi, a former federal prosecutor, agreed that Mueller likely meant for Congress to tackle obstruction and told TPM that Barr should have recused himself from making the decision.

“Why should he have recused? Because last June he made the decision that there was no obstruction,” Rossi said, referencing the 2018 memo. “What Mueller said was there are arguments on both sides. And I think Robert Mueller wanted Congress to decide that.”

In the Sunday letter, Barr wrote that he had consulted with the Office of Legal Counsel and Rosenstein in making the decision.

Barr argued in the letter that Mueller’s decision not to bring a Russian election interference case against Trump was a significant factor in Barr and Rosenstein’s decision not to prosecute the President for obstruction.

The attorney general wrote that Mueller did not find evidence establishing “that the President was involved in an underlying crime related to Russian election interference,” so that “while not determinative, the absence of such evidence bears upon the President’s intent with respect to obstruction.”

Attorneys told TPM that while the legal reasoning in Barr’s June 2018 memo differs from what he used in his Sunday letter, the memo itself colors Barr’s role in the matter.

David Alan Sklansky, a former federal prosecutor and current law professor at Stanford, told TPM that “the idea that it’s a significant factor that theres no evidence that Trump himself was not involved in the underlying interference — that’s a novel and I think unpersuasive view of obstruction.”

Others have jumped on Barr’s interpretation and suggested that his past memo may suggest that the attorney general approached the issue of obstruction with bias.

In a New York Times column published hours after Barr’s letter was released, Georgetown law professor and author of the current special counsel statute Neal Katyal wrote that there was “a serious question of whether Mr. Barr’s decision on Sunday was based on the bizarre legal views that he set out in” last year’s memo.

Former Watergate prosecutor Nick Akerman took a similar view, telling TPM that “he basically imposed his viewpoint on this decision,” and that his perspective in the memo was an example of Barr “basically auditioning to be attorney general.”

Jens David Ohlin, a professor at Cornell Law School, told TPM that Barr “tried to craft his letter to Congress in such a way that it does not rely on the theories he presented in his 2018 memo.”

“Instead, Barr relies on his conclusion that there was insufficient evidence,” Ohlin argued. “But one wonders whether Barr’s prior memo influenced his assessment of the evidence. It seems like his mind was already made up.”