Are you sure you're not falling into the trap of "I didn't see it, so it doesn't exist"?
Sadly, a lot of people in the US watch Fox News and think it is the only truth. (Check out mediamatters.org for some agenda monitoring).
David Koch opposes the Iraq War.
However that is not the only issue causing these bubbles. People are segregating themselves, both socially and geographically along ideological lines. Print media is increasingly losing subscribers to generally less informative mediums such as tv. Technological advances, many brought about by my own field of software engineering, make it easier and easier for people to wall themselves off from ideas that make them uncomfortable. These are much more difficult problems to solve, and I certainly have no definitive answers for them.
So I start where I can, trying to encourage strangers on the internet (and in real life) to step out of their bubble and read the truly important journalism that still exists in our world. In the meantime, I hope someone much smarter than me can fix the divide in the US that causes these ideological bubbles. Because right now we are sitting on a powder keg, and the media isn't the cause... it's an effect.
These criticisms toward the media and 'it's not like it used to be' allegations have been going on for generations.
'Yellow journalism' dates back to before the spanish-american war.