President Donald Trump has escalated his campaign against his predecessor Joe Biden by challenging the legitimacy of documents signed with an autopen.

The move highlights both a legal gray area in presidential authority and Trump’s ongoing effort to symbolically erase Biden’s influence.

Trump posted on Truth Social Friday that nearly all of Biden’s official documents—he estimated about 92 percent—were signed mechanically, without explicit presidential consent. He suggested that Biden could face perjury charges if he claims to have authorised the device.

The autopen controversy extends beyond paperwork. Trump has repeatedly mocked Biden’s use of the device since January, most recently declaring that pardoned Thanksgiving turkeys were “null and void” and replacing Biden’s portrait in the White House “Walk of Fame” with an image of the autopen in action.

While Trump alleges that Biden’s staff effectively managed presidential decisions without oversight, the broader legal implications remain uncertain. It is unclear whether past executive orders or policies signed mechanically can be revoked, or how agencies that implemented them might respond.

Autopens, which allow mechanical signatures, have been used in multiple presidencies and trace back to Harry Truman in the 1940s. Historically accepted as a practical tool, the device is now at the center of Trump’s critique, representing, in his framing, a lack of direct control and accountability.