Midway through Barack Obama’s third year as president, Congress approved a controversial measure related to national security, with just 15 minutes to spare before certain surveillance powers were set to expire. The president, however, was in France when the bill cleared Capitol Hill.

In generations past, this might’ve posed a logistical challenge, but thanks to modern technology, White House officials weren’t concerned: Obama authorized use of the presidential “autopen” to sign the legislation into law. Some House Republicans weren’t pleased, but the administration pointed to a Justice Department guidance, written for George W. Bush, on the legal permissibility of the tool.

For the first time in American history, a sitting president is asserting the right to invalidate a predecessor’s pardons.

In the years that followed, discussion about the use of autopens has largely evaporated, though late last week, it apparently made a comeback: During remarks at the Justice Department on Friday, Donald Trump questioned Joe Biden’s use of the tool, saying that measures signed by his Democratic predecessor might not be “valid.”

Two days later, the Republican incumbent posted an item to his social media platform, suggesting that it was the autopen, and not Biden himself, who served as president for four years.

Shortly after midnight, Trump went considerably further, claiming he was invalidating at least of Biden’s parsons. The message read in its entirety:

The ‘Pardons’ that Sleepy Joe Biden gave to the Unselect Committee of Political Thugs, and many others, are hereby declared VOID, VACANT, AND OF NO FURTHER FORCE OR EFFECT, because of the fact that they were done by Autopen. In other words, Joe Biden did not sign them but, more importantly, he did not know anything about them! The necessary Pardoning Documents were not explained to, or approved by, Biden. He knew nothing about them, and the people that did may have committed a crime. Therefore, those on the Unselect Committee, who destroyed and deleted ALL evidence obtained during their two year Witch Hunt of me, and many other innocent people, should fully understand that they are subject to investigation at the highest level. The fact is, they were probably responsible for the Documents that were signed on their behalf without the knowledge or consent of the Worst President in the History of our Country, Crooked Joe Biden!

There’s a lot to unpack in this 158-word harangue, and there’s probably no point in highlighting every individual error of fact and judgment. The bottom line, however, is relatively straightforward: Trump claims that Biden didn’t actually sign pardons for members of the bipartisan House Jan. 6 committee, so as far as the Republican is concerned, prosecutors are free to go after them, despite the fact that there’s literally no evidence that they did anything wrong.

The entire pitch is based on the president’s apparent belief that (a) his immediate predecessor used an autopen to sign the pardons; (b) documents signed by autopens don’t count; and (c) Biden suffered from mental deterioration to such a horrific degree that he wasn’t aware of his own policies and preferences.

The first point is dubious, given that there’s no evidence that Biden used the tool to issue the pardons; the second point appears unsupported by law; and the third point is offensive on its face.

But let’s also not lose sight of the forest for the trees: For the first time in American history, a sitting president is asserting the right to invalidate a predecessor’s pardons.

In other words, as the United States deals with a sustained offensive against the rule of law, Trump has made up a new power for himself that does not exist.

To be sure, there’s often a disconnect between what Trump says he’s doing and what he’s actually doing. The Republican has now claimed in writing that he’s voiding some Biden-era pardons, but given recent history, it’s entirely possible that in the coming hours and days, the White House will pretend he never actually published such a message. Perhaps, in other words, this radicalism will soon be forgotten.

But if Trump seriously takes steps to undo Biden’s pardons, because he feels like it, the coming fight will be dramatic.