What we don't know about Mueller probe > What we do

Washington (CNN)In politics, there's a tendency to assume that what is publicly known is everything there is to know. Twitter, cable TV and lots and lots of ambitious politicians ensure that no strategy gets left unexplored, no thought gets left unvoiced.

That assumption of knowledge has infected how the political world approaches the ongoing special counsel probe into Russian interference in the 2016 election and possible collusion between the Russians and the campaign of Donald Trump.
But that frame fails when it comes to understanding what exactly special counsel Robert Mueller is doing in regard to the investigation. Mueller and his team are the rarest of rare commodities in modern Washington -- a closed universe without leaks.
We were reminded of that fact Wednesday afternoon when ABC reported that the special counsel had investigated -- and is no longer investigating -- Attorney General Jeff Sessions for possible perjury over his description during confirmation hearings of interactions with Russian officials in the course of the 2016 campaign.
    Wait, what? We didn't even know Sessions was under any sort of investigation -- much less that he may have been cleared! 
    That's been the pattern time and time again with the Mueller probe. Most people -- even in politics -- had never heard of George Papadapoulos before Mueller's team filed documents detailing the plea deal in which the former foreign policy adviser to the Trump campaign pleaded guilty to lying to the FBI and agreed to cooperate with the Mueller probe. Ditto the plea deals for former Trump national security adviser Michael Flynn and former deputy campaign chairman Rick Gates as well as the indictment of a baker's dozen of Russians allegedly involved in a broad-scale effort to interfere in the 2016 election.
    The Point: Mueller is operating a criminal probe, not a political campaign. The rules are different. He and his team know a whole heck of a lot more than is publicly known. All of the rest of us are just trying to piece together the tidbits, but Mueller sees something much closer to the full picture.