@Kevin Turnquist
There is a small but significant proportion of the US population who are well educated, including many who visit this site. My apologies to you, please don't taking this personally.
In the US, European qualifications have a higher standing than their local equivalent, a US Masters degree generally reguarded as equivalent to a UK Honours degree and a UK Masters degree viewed as superior to its US equivalent. And of course some areas of the country are 'educating' their children in the 'science' of Intelligent Design.
Beyond the well-educated minority, people, as in Europe, get their knowledge from the TV. Over here we get the best of the US TV shows, so you can imagine how good the rest is. As a country the US is very insular - non-US news gets a very short slot at the end of a (say) 30 minute news show and a lot of that is of the 'and finally' variety, and even then is frequently featured only because the US is involved in some way. Your average working class American is, unfortunately, educated to a lower standard, fed lower standard entertainment and is not very well informed about the rest of the world. The fact that religion still has a big hold in the country is a sign of all of this - well-educated people question more and are less likely to accept religious teachings at face value. Some states are like a large ghost town on a Sunday because large swathes of the population go to church. I'm not saying that belief is wrong or bad, just more prevalant in a poorly educated society.
You asked how I can make these judgements. Well I spent the best part of a year living and working in the US a few years ago. The ignorance of the outside world - that beyond the US border - of the average US citizen is truly frightning but you have to experience it firsthand for a while to appreciate how bad it is. The only redeeming feature is that with their current approach to education and the reporting of current affairs the US is likely to fade in influence over the years. Which is just as well when people like George Bush Jr can get almost elected as the most powerful person in the world...