Can you tell what is illegal here?
1. VP Pence, presiding over the joint session (or Senate Pro Tempore Grassley, if Pence recuses himself), begins to open and count the ballots, starting with Alabama (without conceding that the procedure, specified by the Electoral Count Act, of going through the States alphabetically is required).
2. When he gets to Arizona, he announces that he has multiple slates of electors, and so is going to defer decision on that until finishing the other States. This would be the first break with the procedure set out in the Act.
3. At the end, he announces that because of the ongoing disputes in the 7 States, there are no electors that can be deemed validly appointed in those States. That means the total number of “electors appointed” – the language of the 12th Amendment -- is 454. This reading of the 12th Amendment has also been advanced by Harvard Law Professor Laurence Tribe (here). A “majority of the electors appointed” would therefore be 228. There are at this point 232 votes for Trump, 222 votes for Biden. Pence then gavels President Trump as re-elected.