These are recounts, audits, and security guards. No recounts deviated by that much, even the massive Arizona recount found no significant deviation.
> It is not difficult to find historical precedent of election fraud
Please provide that. The evidence AFAIK is counted as essentially "parts per million", it is so small. Meanwhile there are a variety of safeguards, audits, verifications & recounts.
The null hypothesis in this case I don't believe would be "fraudulent election", so it is a claim.
In the aftermath of this clearly deceptive behavior, they've maintained the support of Republican voters who still believe the lie despite none of the evidence ever being released.
It's one thing to claim something is true and that you have evidence, then release the evidence and find out that it's insufficient to win in court. It's another thing entirely to make a claim, say you have overwhelming evidence to support it, and never release any evidence at all. In the former case, maybe you got overzealous or maybe you were dealing with an unsympathetic judge. In the latter, the only rational way to interpret the situation is that you were intentionally misleading your audience.
In the scientific world, a hypothesis that has no evidence is treated with skepticism.
In the rest of the world, it gets treated as fact, even as evidence against the claim pours in.