Mueller has already found a lot of something, but... There is a real question of whether there will be enough specific information to prove, beyond a reasonable doubt, that Trump himself directed it. Trump is a well-practiced mobster. He knows to be indirect with underlings to create "plausible deniability", as implausible as his denials are. Was he in it up to his eyeballs? No doubt, but can it be proved directly? Time, and Mueller, will tell.
