Doesn't seem like it is obvious to you.
Why are porn sales down. Tubes, Torrents, Usenet, File lockers, Knowledge, then maybe then the economy, which itself is mainly the result of bankers that created financial instruments they couldn't control, average joe blog who took loans he didn't understand to buy things he didn't need, regulator who failed to regulate, etc.
That someone would try to blame Bush, Obama or whoever for poor porn sales like you're doing now is a perfect example of how dogmatic ideology has replaced common sense. And if anything that's what is hurting the country.