The logic most liberals would offer would be that regardless of actual ancestral slave status, the general slave status of blacks as *class perception* means that all of them have experienced the damage through the descent of stereotypes, withheld opportunities and racism on through the years. Reparations wouldn't just be for slavery itself, but for the entire effect it has had on social history. And it is all implicated with the idea that it was white slavery of blacks that swept in like this giant boot, artificially stomping down an otherwise would-be prosperous black population from building 'their America'. This is why they hate history, especially when you start to think about why free African blacks have ceaselessly demonstrated their inability to civilize or advance technologically on their native continent - well before any interaction with dreaded whites.