Don’t perpetrate misinformation. The “3/5 of a person” was a compromise for the sake of proportional representation, struck between Northern states, which wanted not to count slaves for Congressional representation at all, and Southern states, who wanted to count slaves fully for the sake of representation in Congress, even though the slaves were not enfranchised citizens. The Constitution does not “regard” black people (or slaves) as 60 percent human.
I understand what you are saying. That is the problem we run into. If you want to go back and try and figure out what the Founding Fathers were thinking, you have to look at what they were doing at the time. That’s where we get into trouble. Did their slaves have the vote? No! Why? When our courts tell us what the Constitution “Really” means, we are in trouble. When the Founding Fathers said “All Men”, that’s exactly what they meant.....”Men” because they didn’t give the women the vote. That’s what I mean about reading the original Constitution.