Well, I did say 'expect'. I happen to believe in social engineering, but it doesn't mean the discipline exists now, so what we get instead is..."garbage in, garbage out" as you eloquently put it
However I do think that the Australian electorate is better informed then the US electorate, possibly because of the obigatory voting requirement.
I would not judge American education system so harshly.
Part of the problem (in my perception) is the inability by some stratae of the American society to relate Federal policies to local issues.