[Olog-hai]

Yes he could have. The Constitution does not in any place require rubber stamping.

And all of the deep state Unipartiers that claim to be conservative could have refused to certify.

[Alberta's Child]

The Constitution requires the VP -- as President of the Senate -- to open the certified electoral votes from each state. That's it. As the 12th Amendment says:

The President of the Senate shall, in the presence of the Senate and House of Representatives, open all the certificates and the votes shall then be counted ...

Guess what -- that really IS it.

The only discretion Congress has is in cases where one state has multiple certified electoral votes. That was not the case in 2020.