There's, unfortunately, no such high bar to reach. Congress can admit a new state using a simple majority if they wanted to.
What's also unfortunate is that the Democrats control the Senate and I would not put it past them to ignore the rules to pass this with a simple majority. Assuming the squishes don't side with the Democrats, they've pretty much got it in the bag.
Their hunger for power knows no bounds; they'll do whatever they want and no one is going to stop them.
(Also note that they only have that majority because they stole at least two Senate seats in the 2020 elections and run-offs).
So, my thinking on this is that whatever fuckery they try to muster is going to be caught by this audit. This is supposed to be a forensic audit. So they will be manually scanning each ballot, doing a manual count, analyzing the machines, and verifying the voter registration for each ballot.
So they can destroy a ton of ballots, but then there will be a huge list of outstanding votes and registrations. The discrepancy should have a distribution that aligns with the ballots that are accounted for.
If those outstanding ballots are 98% Biden... Bam! There's your election fraud.
The other thing is that with the ballot scanning, they're going to be able to tell if ballots are valid or not. They will see if the markings were made by a human and if mail in ballots had been folded and mailed (yes, they can tell if the fold was just made or if it had been sealed in an envelope and handled).
I hope this isn't all wishful thinking, though.
I'm betting it has a lot to do with public perception. There will (or should) come a point where the truth of how they stole the election will be undeniable. This audit, if done properly and fully documented, will make it undeniable. It's going to get out among conservative circles and eventually the normies are going to catch wind of it and wonder why the news isn't reporting on it. So the MSM will have to report on it. Then they'll have to report on how the machine recounts were legitimate but the full forensic audit isn't. It really creates a problem for the narrative. We should see a lot of people waking up then... Hopefully.