Licked

What the book meant by "licked a hundred years ago" means that they had lost the battle in slavery a hundred years ago. Because racism had stemmed, rooted in the firm soil of America and had set its roots into the brains of the youth generation through generation. Because slavery and racism is a political matter, political socialization of political culture has a lot to do with it. In America, your parents (aka family in political socialization) has a lot to do with the way you vote or think politically. Political socialization plays a large role today in our country, too. Back then it did as well. But the fact is that these traditions and values have been passed down through generation, the thinking has been too, therefore that means the parents have been educating the children of these kinds of things, pretty much meaning that they had lost the sway of the people because the people are all already thinking in this preset idea that racism is good, black people bad, etc. Political socialization is a powerful tool, as we follow our parents, what they say. So what he meant by being licked a hundred years ago means that they had already lost the case a hundred years ago.