President Donald Trump is casting doubt on whether he actually swore to fulfill the constitutionally mandated duties of the highest office of the land.

Trump has told numerous aides and Republican congressmen that the voice heard swearing an oath to “preserve, protect, and defend” the U.S. Constitution during his inauguration as the nation’s 45th president wasn’t really his. Instead, the president insists, he was merely lip-syncing to a pre-recorded recitation of the oath performed by a vocal impersonator.

“That wasn’t my voice,” Trump told one senator earlier this year, according to a person familiar with the conversation. “I never swore to do anything for that piece of paper. Besides, what has it ever done for me? Nada. Zilch. That’s what.”

More recently, the president has told various White House staffers that he secretly had someone who sounds like him pre-record the oath, then coerced an audio technician at the inauguration to play the recording while Trump only pretended to speak at least some of the 35 words of the oath as prescribed by the Constitution.

“You can’t say he’s violating an oath to preserve, protect, and defend something if he never actually swore to preserve, protect, and defend it.”

“He said he really did swear to do the ‘Office of President of the United States’ part but skipped the rest of the oath,” one presidential aide said.

Whether Trump didn’t really take the entire oath or is merely attempting to sow uncertainty about what he actually swore to do in office remains unknown. However, some political observers believe the ostensible president did — or is trying to — create a defense against accusations that is he destroying the Constitution.

“You can’t say he’s violating an oath to preserve, protect, and defend something if he never actually swore to preserve, protect, and defend it,” explained Ryan Lizza, of The New Yorker. “Of course, that also means he may not really be the president of the United States.”

While most constitutional scholars are puzzled as to why Trump would needlessly and voluntarily raise doubts about the legitimacy of his presidency, Larry Tribe, professor of constitutional law at Harvard Law School, speculated as to why Trump would do this.

“He did spend several years trying to delegitimize a sitting U.S. president. I guess some habits are just too hard to break.”