Barack Obama saw the nasty new attacks from the McCain-Palin camp coming a mile away.
The clear analogy, I think, is that John McCain thinks as little of the American public as, say, a TV company executive or Hollywood movie producer. The same thought process that leads to Knight Rider 2.0 leads to "Obama-Osama, friend of terrorists!" Oh, sure, they know it's dumb, but they think Middle America will eat it up whole!
Personally, I think (most) of America is smarter and more sophisticated than that.