Observations of possible irregularities in an election are not proof, however, a fairly held election is one in which the votes can be explicitly audited by any of the candidates, and each voter's valid status can be verified after the vote is completed and counted and a winner is declared. Is that true in today's elections? (and was it ever true). If so, any questions can be resolved through executing an audit, and no one needs to seek the Supreme Court.
Allowing the votes of qualified citizens to be counted in an election is part and parcel of operating a fully auditable election. Whatever fully auditable approach offers the fewest obstacles is where we should land, as long as feasibility and practicality are contemplated. At least once, each voter needs to provide evidence that they are a US citizen, and that they reside in the district for which they are voting. Thereafter, there needs to be an auditable trail connecting their vote with their eligibility.
> a fairly held election is one in which the votes can be explicitly audited by any of the candidates
You're confusing a verification procedure with an outcome. A fairly held election -- i.e., the outcome -- is simply one in which the pollsters and voters adhered to all the rules. And it is possible for an election to be fairly held that is not auditable. Sure, it might make people feel better post hoc about whether it was fair, but that doesn't mean that an unauditable election cannot be fairly held.
We've largely had non-auditable elections throughout our nation's history, and we've survived reasonably well thus far as a democracy. If there were past evidence of fraud that might be serious enough to change the outcome of an election, then the case for strict auditing would be much stronger. But to date, compelling evidence of fraud has never appeared.
Allowing the votes of qualified citizens to be counted in an election is part and parcel of operating a fully auditable election. Whatever fully auditable approach offers the fewest obstacles is where we should land, as long as feasibility and practicality are contemplated. At least once, each voter needs to provide evidence that they are a US citizen, and that they reside in the district for which they are voting. Thereafter, there needs to be an auditable trail connecting their vote with their eligibility.