In 1992, Brian Springer spent over 500 hours capturing direct satellite feeds of the video clips that powered both news broadcasts and that year's presidential campaigns. By manually monitoring the video feeds and recording selected highlights, he created the raw footage that he would then turn in to a documentary entitled "Spin".
The film is less than an hour long, and amazingly, you can watch it in its entirety on Google Video.
Though some of the techniques seem laughably primitive now, and the efforts of the 1992 campaigns (hey, remember Ross Perot?) are kind of dated the day after the YouTube debates, this is still amazingly resonant. I couldn't vote yet during that election, but now that I'm old enough, I try to be aware of the effort that goes in to crafting these carefully-honed messages. Even with that awareness, seeing the actual footage of that work in progress is incredibly creepy.