> (My suspicion is that an ability test would lead to a less racist outcome than requiring college. Why? Because minority families struggle more to afford college.)

This might have been true when the United States was mostly white, and "minority" specifically referred to the black population who was mostly descended from slaves brought to the US mainland pre-1808, or to an even small number of native Americans. Today, when the US population is significantly more ethnically diverse, and "minority" just means "anyone nonwhite, regardless of where they came from or what their family history is", there's a lot more variation in exactly how ability to afford college correlates with ethnicity.