It is not a scholarship. It is a need-based-grant system that is Ivy-wide based on multiple factors, ranging from what your parents make to the value of their house to anything your family may have saved up for your tuition. If you do get a scholarship, say from a competition you won or an essay you wrote, the Ivy college will count that AGAINST your aid package in a negative way and give you less money, so the only time scholarships help at an Ivy League, is when your parents make so much money, you don't get any aid package. That, or just for the prestige.
Are most kids who go to Princeton from rich families? Absolutely.
Are all of them? No.
Is Cabral? No idea, don't know him. All my knowledge of him are anecdotal and second or third party. Although, all of them agree, he is an elitist conceited ass, so my money is on rich kid.....