A lot. Federalism in the US got progressively softer until the early 20th century, when the power and reach of the federal government massively expanded and the autonomy of states shrunk in proportion. Congress and the federal regulatory agencies have a lot of power over individual states. A number of Supreme Court rulings, incorporation of the Articles, federal agencies, power of the purse, and largely broadened definitions of congressional power give congress wide-sweeping power to dictate law and policy in states. They have much, much more power over what goes on within the 50 states than they have over foreign governments. The US isn't a collection of largely independent sovereigns and hasn't been since the late 18th century.