Pseudo-Environment of a Pseudo-Event

I think the first barrier to "truth" is that the press conference itself is what Boorstin called a "pseudo-event" - an event that would not occur without the media there to record it. It's not a spontaneous happening that these journalists are trying to record. The whole event is contrived from the moment the president and his advisors (or really anyone giving a press conference) decide they are going to hold a conference. The topic is generally well-defined before the reporters show up. And even if reporters want to ask questions off topic, it's unlikely to last for long (and they may not be asked back if they ask too many uncomfortable questions). The speaker (in this case the president) is often rehearsed with prepared statements and pre-formulated answers to questions that support their point of view.