"Republicans argue that since their observers couldn’t watch the vote count, they can’t provide that evidence and have asked for discovery. Still, while the courts have agreed that irregularities have occurred, they weren’t willing to grant discovery unless Republicans first present enough evidence of fraud to overturn the election. Republicans thus faced a kind of Catch 22."
Source: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3756988
Surely some amount greater than zero would be a start, however. Citing statistics isn't a great first choice, since it's so easy to retroactively fit statistics to whatever outcome you want to see. Fraud on the scale you are alleging would leave a hell of a lot of evidence that couldn't possibly be completely swept under the rug. A misapplication of Benford's Law is a really weak argument.