This New York Times essay by Eric Posner is the most thoughtful treatment I’ve read of the case against prosecuting Donald Trump.

The most striking and troubling feature of the calls for prosecution is how few of them are rooted in actual and specific accusations of criminal activity. Moreover, for those who simply want Trump to suffer for his sins, the most condign punishment for a personality so constituted is irrelevance. It is unclear whether that is possible given the intensity of his support. But how intense that support will remain when he shuffles out of the Oval Office in an increasingly pathetic spectacle of denying that he is the worst thing one can be in the Trump ethos—a “loser”—is unclear. As Posner notes, the outcomes in a prosecution—acquittal or martyrdom—are both wins for Trump.

I would offer some refinements, mainly based on disagreements with Posner’s wide-ranging view of executive prerogative, which he and Adrian Vermeule articulated most fully in The Executive Unbound. Posner writes in the The Times that “the constitutional powers of the president are extremely vague and have been interpreted expansively by generations of lawyers and judges on the left and right.” That reference to “lawyers and judges” is significant. It is relevant, in this context, because Posner is talking about a prosecution. But presidential powers are not “extremely” vague. Article II articulates them with reasonable clarity. There is some shadow involved, certainly, but it is “extreme” only to the extent one wants to pack Lockean prerogative into the word “executive.”

But if, as Ben Kleinerman and George Thomas would remind us, we look at the Constitution politically, this is less a legal than a prudential question. It is unlikely that any president can serve four or eight years in office without violating the law. Thomas Jefferson wrote that a president may in fact be morally compelled to do so and to “throw himself on the justice of his country and the rectitude of his motives.”

Note that Jefferson does not claim, nor did Lincoln, that prerogative constitutes a get-out-of-jail-free card. Breaking the law is still breaking the law, and it entails accountability—whether criminal or political. The key, rather, is a prudential—not a strictly legal—assessment of motives. In that vein, I would distinguish between purported crimes of a personal nature—like bribery—and allegations that an official act broke the law. Prosecuting every case of the latter without prudential discretion, in the style of Inspector Javert, would require locking nearly every president up.

If Trump can be shown to have committed a clear crime of personal benefit, similar to bribery, prosecution would still require a judgment about justice and the public good. But prosecuting official acts in a criminal court rather than in political forums like impeachment and elections is a dicey business. So, in either case, is demanding prosecution while neglecting to allege a specific crime.