Cruz worked on Bush v. Gore. He is also very well-versed in the Constitution and election law. If you get a chance to listen to him speak about the matter, listen.
He is convinced there is irregularities. It may be negligence. It may be fraud. It might be just an honest mistake.
But three thresholds have to be met:
Fraud must have occurred. The cites must be specific, with evidence.
That fraud must be sufficient to impact the outcome of the election.
A remedy must be available.
Therefore, you can have am amazingly crooked election, that cannot be overturned.