When they wrote that general welfare meant the general welfare of whites only.IMHO, general welfare means everybody. It means you don't benefit one group but not another, whether it's by state, race, religion, gender, or any other discriminator. It does NOT mean equal outcomes.
But that changed.
Several years ago I visited Monticello, Thomas Jefferson's estate in Virginia. I was impressed that they didn't shy away from the obvious contradiction of Jefferson's life. The man who laid down perhaps the most eloquent and persuasive defense of individual liberty, was a slave owner. I mulled over it for some time, but came away with a renewed appreciation for the power of ideas. Jefferson's convictions about the value of individual liberty were, ultimately, at the heart of the movement to abolish slavery - the very institution that propped him up and made him a wealthy, influential person in the new republic.
What I took away from this was a new appreciation for the power of ideas. Ideas and ideals can transcend, even contradict, the circumstances and trappings of those who carry them. Jefferson's logical conclusions about the morality and justice of individual liberty eventually undid the very social structure which propped him up. I find that really beautiful and inspiring.