While attempting to appear intellectual and thorough, Nelson justified the racial judgements of SCOTUS by arguing that the court was merely doing what it should do and was not racist. Read it to be aware of his perceptions, but not to arrive at an accurate accounting for the reasons certain decisions were made.
Probably the best thing about this book is the title. People looking for a history of the Fourteenth Amendment are drawn to it.
But then when you read it, it's like the author has never encountered a political debate before. It turns out (much to the author's apparent surprise!) that there were multiple sides to the argument over the Fourteenth Amendment. And the sides all tried to argue all the arguments: natural law, big change, small change, &c., even though they were incompatible with each other and the same arguments that their opponents were making.
Shock! Surprise!
There are no conclusions other than that everyone had a lot of arguments but none of them were really Lochner.
The author's research didn't really go anywhere. Sure life on the ground is always complicated but I don't even think the author tries to make that lesson clear.