They will not overturn/invalidate an election.
I'm a very prideful person, the thing i hate most is to be wrong. But i'm praying to be wrong on this but i don't see this shaking out like everyone thinks… SCOTUS will not invalidate an election and will likely only have limited power over the states to do the same under the rules of the constitution.
The whole purpose for mass mail-in voting was to have legit ballots to perform the fraud with. Before they had to manufacturer the votes… now they have them, they just have to count them. There is nothing that can be done here aside from certifying EVERY single ballot in the swing states.