The obama administration endorsed state-centered federalism by:

The Obama Administration endorsed state-centered Federalism by choosing not to enforce federal criminal law where States had chosen to legalize certain activities or goods. One significant example are laws regarding medical and recreational marijuana. The Obama administration did not prosecute actors who were engaging in the industry, both as consumers or firms, in states where their activity had been legalized, although it had the right to prosecute under federal law. 

The mercantilism option