You are far to generous in your assessment of how many Americans are actually economically literate. I would put the number much closer to 10% I have for many years subscribed to the "90-10 rule". It means that 10% of the people are aware and 90% haven't the first clue what is going on around them either locally or in the world generally.
You're right 90% think that the government pays for retirement (SS), healthcare (Medicaid, Medicare), housing for the poor (HUD) and general welfare (AFDC). They also think that the government creates jobs.