I agree with what you're saying here, just want to add that your example also kind of upholds the original line. Delivery, audience, tone, implication/insinuation factors all matter a ton... but in a text medium, barring access to any of the above, we kinda assume that if someone's white, upper-middle class and well educated, they're at least a little prejudiced against black people. Which was the original point.
(For bonus points I likewise kinda assumed with nothing to go on except the broader context that our "white, upper-middleclass college graduate" is going to be male and likely middle-aged or older.)
(For bonus points I likewise kinda assumed with nothing to go on except the broader context that our "white, upper-middleclass college graduate" is going to be male and likely middle-aged or older.)