I get the argument from the perspective of power politics, the idea that in governments of consent ultimately the one who holds the gun has the power.
But
John Kowalski asked "Is trump lying?"
If the President of the United States makes a statement about the powers of the vice president, and someone asks, "Is he lying?" I think it's appropriate to state that as, yes, the president is lying -- the Vice President is not authorized those powers by the law the grants the Vice President his role in tomorrow's count. What Trump is saying is a lie.
But, of course, Trump also holds the nuclear football. Trump's power to launch thousands of nuclear weapons around the globe, aiming them at every state that voted for Joe Biden in this election, a power that he alone on Earth holds, does not suddenly make every lie a truth. Trump is lying.