In other words, the report is strong in theory, but perplexing in application.

Of course, a criminal prosecution of a president cannot proceed without recognition that it is no small matter for a prosecutor to put at risk a democratically elected government. At the same time, the report contains a wealth of evidence that the president disregarded the law whenever it suited him, and especially whenever it was in his personal and political interest.

In any normal case like this, the amount of detail of bad or shady character would have swung the case very much against the president. He routinely lies and urges other people to lie; he directed his White House counsel to fabricate evidence that he had not ordered the counsel, as he indeed had, to arrange for Mueller’s dismissal. While it is true that prosecutors should prosecute crimes and not people, they rarely fail to be affected by evidence that the person under investigation routinely hatches criminally questionable schemes. The Mueller report certainly seems to support the proposition that a president can expect the benefit of the doubt in this respect.

Here, after all, is a report in which the prosecutor concludes that the “President’s efforts to influence investigation were mostly unsuccessful, but that is largely because the persons who surrounded the president declined to carry out orders or accede to his requests.” This is a remarkable statement. If he were still the chief executive of the Trump Organization, it would not have worked well for Trump to defend against multiple criminal accusations by noting that his staff sometimes intervened to stop him. For the chief executive of the United States, this peculiar argument seems to have some bite.

David A. Graham: No one listens to the president

In fairness to Mueller, his report is a product of the cycle of adjustments made to the mechanism for investigating presidential misconduct. The Watergate episode suggested the need for an independent process, free of conflict of interest. This ushered in the period of the “independent counsel,” which later came to be seen as fraught with dangers of partisan overreach, and a presidency hobbled beyond reason by sustained, expensive, and at times ill- motivated investigations. Once that statute was allowed to die, the special-counsel regulations under which Mueller operated were meant to provide some measure of independent enforcement, while restricting the avenues for partisan misuse.

Now a special counsel reports to the attorney general, making him an employee bound to follow his superior’s orders and to comply with Justice Department policies and standards, including the OLC immunity opinions. He reports his conclusions on a confidential basis: Only the attorney general can authorize a public release. The special counsel must refrain from expressing a judgment about potential impeachable offenses. Just as the independent-counsel law after the Watergate period was an answer to the lawlessness of the Nixon administration, so the special-counsel rules respond to the excesses of Ken Starr and the Clinton impeachment. Mueller was operating within a network of built-in limitations.