This Chapter involves several aspects of Congress' power to enforce the Amendments enacted immediately after the Civil War. The main concepts are:
Congress has special powers to enforce the Civil War Amendments, i.e., the 13th, 14th, and 15th Amendments.
Congress probably can't prohibit purely private discrimination under the 14th and 15th Amendments.
But Congress can prohibit purely private discrimination under the 13th Amendment, if it finds that the discrimination is a "badge or incident of slavery."