Norman Solomon goes through the presidential war rhetoric and the way the American media acts as a propaganda wing of the government. The key point is that when media just reiterates what the government is saying and acts in concert; the media isn’t acting as a check on the government, it is an enabler.
It should be said that there are independent news outlets, such as Democracy Now! or The Real News that do a much better job. However, these sources remain outside the mainstream. The most glaring difficulty I see is the news media has a tremendously tough time sorting through an official news source that lie to them. This difficultly has arisen mostly due to time constraints. There is literally less effort going into each news story today compared to the past. This is part of the Rupert Murdoch revolution in mass media.
The most serious aspect of propaganda is not what is included, but rather what is left out. If we are unable to cull those who are consistently and unapologetically wrong, we will forever be hamstrung dealing with unending mountains of false or misleading information.