Bo, the argument, made broadly, is that solicitation to commit election fraud is election fraud.
If solicitation to do so is a crime, then surely coercion to get somebody to commit election fraud is also a crime. Both of those things were heard to have been done - the first with the push to just say that they'd reexamined the results and now have a different conclusion; the second with the suggestion of criminal charges if they don't change things somehow.
From TPM in a visible part of a members only column:
It was pretty transparently clear that the source of the Trump-Raffensperger recording was Raffensperger and staff lawyer Ryan Germany. But it’s notable that in the follow-on reporting they aren’t being coy about it. They are basically saying, we’d been asked to commit illegal acts in earlier calls. It seemed prudent to record this call. Probably the best way to see this is that the two men decided to wear what amounts to a DIY wire.
I don't know any lawyers who deal with solicitation and coercion cases who feel that call was legal. That includes one former FEC lawyer.