It's circumstantial evidence (and the truly laughable part of this exercise is that not only is there a mountain of circumstantial evidence there is also compelling direct evidence). And news flash to Trump cult members, the purposeful obstruction of fact-finding is also circumstantial evidence of wrongdoing and that exists in droves here.

For these people, they expect that the only provable means is if every internal text email and phone transcript starts in all caps with "THIS IS A QUID PRO QUO COMMUNICATION" and at the end there were signed written contracts memorializing the arrangement. It's absurd.