Here's the quote from a 2001 chicago radio interview in it's context. You can google it or try youtube for the audio.
“But, the Supreme Court never ventured into the issues of redistribution of wealth, and of more basic issues such as political and economic justice in society. To that extent, as radical as I think people try to characterize the Warren Court, it wasn’t that radical. It didn’t break free from the essential constraints that were placed by the founding fathers in the Constitution, at least as its been interpreted and Warren Court interpreted in the same way, that generally the Constitution is a charter of negative liberties.