In May 2017, after President Trump learned from then-Attorney General Jeff Sessions that Deputy Attorney General Rod Rosenstein had appointed special counsel Robert Mueller, Trump “slumped back in his chair and said, ‘Oh my God. This is terrible. This is the end of my Presidency. I'm fucked.’”
According to the report, "The President returned to the consequences of the appointment and said, 'Everyone tells me if you get one of these independent counsels it ruins your presidency. It takes years and years and I won't be able to do anything. This is the worst thing that ever happened to me.'"