The way I see it, sensationalism is an adapted way of life for publishers of news. News has always been based upon discord, war, strife, etc. This is partly because discord, war, strife, etc are the only real factors that cause change in human lifestyles. If the president decides to lower taxes, not much happens. If, however, taxes are raised, people become agitated. Agitation means that people are going to have opinions. Opinions mean that newspapers are going to write more articles about people's opinions, using a great deal of hyperbole, causing people to have opinions about their own opinions.
Of course, all this gets the papers and TV agencies lots of $$.