You know what. If i had to choose only one thing that my kid could learn at age 8:
1) Form his own opinion.
2) Long division.
You can pretty much teach any person to do long division in about 5 minutes. It's a series of steps that lead to a concrete and conclusive answer; no difficulty whatsoever involved.
Forming your own opinion though. Whew that is tough. I can kind of see your point about the president being on a pedestal an all, but no one is on a higher pedestal than you, in the eyes of your kid. You having extreme reactions to this kind of thing may be hurting your kid more than anything. Then again, it may not be; probably though, it is. If you just helped your kid along to think by asking him questions and offering him your (and/or other alternate) point(s) of view, you may find your kid a step ahead in his ability to be un-sheeply.
Then again, with a world population of almost 7 billion, no matter how much of a non-sheep you think you are, most likely you are anyway.
In your quest to keep yourself, your family and your kids from becoming sheep, remember, there are some people who are definitely not sheep. They are leaders, by definition the opposite of a sheep. One such person, who is not a sheep, is the leader of the free (American) world. He is known as President Obama.