SDN,
In the article you cited, he said he was not ready to scrap it. Further, he didn’t say it was a mistake, just that it wasn’t working out the way it was intended, whatever that’s supposed to mean. There’s nothing to indicate that he’s changed his position on its constitutionality or inherit goodness, wiseness, and justness, just, perhaps that the genius of the people has somehow thwarted it.
The sad reality is that there is no decent motives to be ascribed to the men who wrote and fought for that legislation.