Seemingly, the desire for detailed news reporting and analysis has waned in the culture since CNN at the beginning strove to become the respected "BBC" of the West, with a reputation for honest, fair, objective, detailed reporting that went to the source for the facts but now has incorporated popular and trendy modes of news commentary.
I was a fan of CNN in the early days, but now I can't tell the difference between it and entertainment. Entertainment that's not that...entertaining. They, along with other networks, have definitely responded to the boom in social networking and the culture change that has accompanied it. Allowing viewers to "tweet" their thoughts about a story or issue and then reading them on air, the "iReport" segments where viewers do the actual reporting and send in video, and the use of Facebook as an interactive part of the broadcasts are all ways they have tried to cash in on the social networking craze. Actual news and constructive dialogue got lost somewhere in the shuffle, unfortunately.
One way the culture has changed CNN is the wide array of news sources, both on television and radio, which have caused CNN to lose viewers. This is true of the network news broadcasts, as well, and all of them have to do dramatic things to keep and grow their viewing audience. The more choices people have, the worse it is for each choice unless they are able to re-invent themselves or find ways to create new viewers. CNN has done that by showcasing liberal commentators and programs as a direct contrast to FOX, as mentioned in an earlier post.
Like the first poster, I am old enough to remember the days before CNN. I think that CNN and US society have changed together, with each influencing the other. The one way I think I see society changing CNN is in how CNN has become something of the liberal TV channel.
When CNN began, the US was more moderate politically and people tended to be more trusting of the media. The media would try harder to be more objective. Now, our society has become more polarized and I think CNN has changed with that. It knows that Fox News has the conservative audience wrapped up and so it has become more liberal as a way to keep its ratings relatively high.
I hope this question gets moved to the Discussion Forum! I would be very interested in hearing other peoples' responses to this interesting thought.
My immediate response would be that CNN has changed American culture more than American culture has changed CNN. As someone old enough to remember the world before CNN, I am still amazed by the immediacy and availability of news information from around the world coming from CNN and its imitators. I think the American culture has been profoundly affected by the increased awareness of conditions and events in parts of the world that had, in the past, seemed very far away and not really connected to our lives.
To address your question, I think CNN has been forced to expand its format and mediums used to present its reporting as its audience has become dependent on alternatives to television as news sources.