
One of the best ways of controlling dissent may be to ensure that it never has a chance to develop in the first place. This can be achieved by preventing people from obtaining information that is contrary to state policies and agendas - if they only know what you want them to know, they are more likely to support the policies you are pushing.
Here, "corrosive" refers to the ways in which the free press has directed criticism and doubt towards the Bush administration. One of the most disturbing themes repeated so often by the Christian Right in America has been the idea that distrust of the government and dissent from the administration qualifies as a lack of patriotism — or even a sign that one is on the side of the enemies.