Americans are really bad at estimating demographic groups.
It would be interesting to do such a poll here. I am sure we would also over-estimate, but surely not so badly.
If you groups responses together, then Americans think:
- 20% are millionaires
- 59% are gay, lesbian or bisexual
- 57% are Jewish or Muslim
- 97% are Black, Asian or Native American
- 92% live in Texas, NY or California