One thing we know about President Trump is this: He is not a forgiving man.

His list of grievances — real and imagined — seems to grow every day, his Twitter feed a never-ending recitation of enemies, old and new: Hillary Clinton, former FBI Director James Comey, Special Counsel Robert Mueller, The New York Times, The Washington Post, CNN, Rosie O'Donnell, and on and on.

The president is vindictive, and proud of it.

And yet Trump, like all presidents, possesses the power to offer clemency for federal crimes. Pardons are acts of lenience and grace, qualities we don't normally associate with this president. So, naturally, Trump uses his authority in distorted fashion, in ways that seem designed to actually decrease the net amount of mercy and justice in the world.

For example, The New York Times reported over the weekend the president is considering offering Memorial Day pardons to U.S. military veterans accused — and in some cases, convicted — of war crimes "including high-profile cases of murder, attempted murder, and desecration of a corpse."

Memorial Day, of course, is meant to honor the valor of American troops. Trump would use the holiday to instead highlight acts of dishonor — and to reward them.

"Presidents use pardons to send messages," Margaret Love, a pardon attorney in previous presidential administrations, told the Times. "If this president is planning to pardon a bunch of people charged with war crimes, he will use the pardon power to send a far darker message."

Indeed, the proposed Memorial Day pardons follow on the heels of other recent acts of Trumpian clemency: In the last few weeks, the president has pardoned Conrad Black, a former newspaper publisher who wrote a really nice book about him, as well as Michael Behenna, a former Army lieutenant convicted of killing an Iraqi man in his custody. Trump in 2017 also pardoned Joe Arpaio, the former Arizona sheriff and immigration hardliner convicted of contempt of court because he refused to stop his department's racial profiling of Latinos.

In other words, Trump uses his pardon power to troll political opponents, reward friends, and to eliminate constraints on his agenda. The proposed Memorial Day pardons would be more of the same.

Among those being considered for clemency are Navy SEAL Special Operations Chief Edward Gallagher, who is awaiting trial on charges he killed unarmed civilians; Nicholas Slatten, a former Blackwater security contractor, convicted for his part in a 2007 shooting spree that left 14 Iraqi civilians dead; and a group of Marine Corps snipers charged with urinating on dead Taliban fighters.

Most of these cases have not yet gone to trial. In other words, if he proceeds with the pardons, Trump will be signalling that issues of guilt or innocence are irrelevant to his decision-making. Even the president's ostensible allies are warning against such premature pardons.

"These cases should be decided by the courts, where the entirety of the evidence can be viewed," said Rep. Dan Crenshaw (R-Texas), himself a former SEAL. "Only after that should a pardon be considered."

When paired with his administration's efforts to undermine the International Criminal Court, as well as the president's own lawless rhetoric on warfighting, pardons in such cases would send an unmistakable message that the United States will not be constrained in its dealings with the rest of the world — not by domestic or military law, not by international law, and not even by conventional understandings of morality.

It's a dangerous stance to take.

Pardons aren't going to be popular, as a general rule. After all, they're given to people accused and convicted of federal crimes. It's easy for an act of clemency to look like an abuse of power — remember former President Bill Clinton's pardon of Marc Rich? — or insufficiently tough on crime. But the Founders gave the president clemency power because they recognized that the legal system could sometimes produce bad results, and that sometimes "a mitigation of the rigor of the law" is required to serve real justice. Without the possibility of clemency, Alexander Hamilton wrote, "justice would wear a countenance too sanguinary and cruel."

In other words, presidential pardons are supposed to reduce cruelty. Trump would reward and encourage it. In this president's hands, it seems, even the power of mercy can become ugly and twisted.