The congressional investigation into the Biden White House’s autopen use could chip away at his last line of defense.

Ky., used a digital signature to send out letters and subpoena notices related to the Biden autopen investigation.

Comer using an autopen to investigate an autopen is just so James," one House Democrat said, mocking the Oversight Committee chairman.

A 1983 article in The Washingtonian traced the autopen’s presidential use back to the “polygraph” device Thomas Jefferson invented to have his writing simultaneously copied. “Every President from Kennedy on has relied on the Autopen to help satisfy the enormous demand for his signature,” the article stated.

Ky., blasted NBC reporters for a story equating his digital signature with the Biden administration's controversial autopen practices.

Joe Biden said every pardon and commutation he issued was his decision, calling Republican "liars" for alleging his aides illegally used an autopen.

A New York Times story published over the weekend showed that Fox News correspondent Peter Doocy was on to something in early June when he raised the issue of the Biden White House's use of the autopen in relation to pardons.

President Donald Trump has claimed that the thousands of pardons signed during the Biden administration are void, due to alleged autopen usage.