>> very, very good friends with comey, which is worrisome. >> reporter: they deny it. it's part of the landscape as he investigated the president. >> in congress, we say politics infects and invades everything. >> reporter: it has. news of text messages of trump led mueller to remove a member of his team. >> i think they are devastating. they are beyond showing political preferences. it, very much, impacts people's perception of fairness. >> reporter: then the president declassified a document challenging the fbi's behavior. >> i think it's a disgrace, what's going on in this country, i think it's a disgrace. >> reporter: the intended message to mueller was clear, your investigation is contaminated. mueller remains silent, instead, letting his work speak for itself. >> he is the best hope to