A proposed federal statute would prohibit all types of discrimination against black persons on the basis of their race in every business transaction executed anywhere in the United States by any person or entity, governmental or private. Is this proposed federal statute likely to be constitutional? 
Yes, because it could reasonably be viewed as an exercise of Congress's authority to enact laws for the general welfare.  Yes, because it could reasonably be viewed as a means of enforcing the provisions of the Thirteenth Amendment.  No, because it would regulate purely local transactions that are not in interstate commerce.  No, because it would invade the powers reserved to the states by the Tenth Amendment. 