Article II - Section 1

"Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress: but no Senator or Representative, or Person holding an Office of Trust or Profit under the United States, shall be appointed an Elector."

States that made election law changes without going through the legislature held invalid unconstitutional elections and must have their electors voided. State governors or supreme courts do not have the authority to change election laws and procedures. This is a stronger argument than fraud occurring, because it is inarguable. Pennsylvania extended their mail-in deadline until 6 days after the election, this change was not passed by the legislature. There is absolutely no argument against it, that is what happened. Someone could argue it should be counted anyway, but they can't argue that the state conducted a valid constitutional election.