The question isn’t whether there was fraud favoring Democrats, it’s whether it was significant enough to make a difference and whether it can be identified.
I suspect it was, but these establishment Dem metro areas are expert at cheating. In Pennsylvania, they not only unconstitutionally liberalized the election laws in the middle of the election season, but this liberalization made it much easier to cheat if you could keep the polls watchers from seeing what was happening.
One example, mail-in ballots in Pennsylvania were supposed to separate ballots received before the end of election hours and those arriving later per the SCOTUS. Instead, Pennsylvania has no idea if the rules were followed, whether late arriving ballots were separated, all while envelopes were discarded, and everyone claims to have no idea. It appears to be a choreographed effort to permit cheating and mishandling of ballots with significant partisan involvement.
I‘m absolutely certain it won’t happen, but the only fair way to determine this election is to re-vote for President and Senate*(where applicable) in Pennsylvania, Georgia, Michigan*, Wisconsin, Arizona*, and Nevada. There were too many voting irregularities to determine a truthful outcome in those states. I think that would be more acceptable than a court ruling ballots being disqualified. Voting audits are likely more practical to determine fraud in hindsight.
More importantly, election processes need far more rigorous oversight than what currently exists in Democrat metro strongholds. It is a violation of the equal protections clause of the Constitutional to permit different standards of election oversight for rural and urban voting districts. Poll watchers need to be given equal access at both elections centers.