However, as a necessary compromise for the formation of a federal union» the states yielded a portion of their sovereign powers to the new federal government, which was created by the Constitution,There was no precedent for the dual system of government which the Americans established in 1789. Consequently to defining and redefining the relationship between the nation and the states has been an ever present problem in American constitutional development.

Federal-state relationships are shaped by two cross-cutting doctrines used by the courts s the preemption doctrine and the abstention doctrine. The preemption doctrine is implied in the supremacy clause of Article VI of the Constitution. It applies to matters which are considered to have such a national character that federal laws must supercede state laws with regard to them. This is the case when Congress exercises its powers enumerated in the Constitution, as it does by adopting uniform laws of bankruptcy, patent and copyright. Thus, if a state law conflicts with a valid federal law, the courts will invalidate the state law because it is preempted by a comparable federal law.

However t when a particular subject knatter is neither explicitly delegated to the federation by the Constitution，nor prohibited by it to the states, the 10th amendment provides that it is then reserved to the states. From this derives the abstention doctrine, under which federal courts relinquish jurisdiction in certain circumstances in order to avoid needless friction with the administration of state affairs.

Although the powers granted to the Congress were stated in the Constitution, the scope of these powers has been a matter of debate for over two centuries. Over the years the Supreme Court has tended to give a broad interpretation of certain general clauses in the Constitution. The “Interstate Commerce Clausew , for example , has become a source of extensive federal labor and social welfare law and even of statutes dealing with racial discrimination. Similarly» the “Necessary and Proper Clause”, which has now become a source of implied federal powers, has led to a far-reaching extension of the express legislative powers.

The economic and social development of the country has also contributed to the expansion of federal power. In recent years，areas which were once under state control» such as agriculture» mining» manufacturing > and labor t have eventually given way to national control when transportation systems and economic markets assumed a national character.8 Over time，much of intrastate commerce has become interstate commerce. Thus，the general trend has been toward increasing the powers of the federation and diminishing the powers of the state.

However, the courts have agreed that the most essential power inherent in the gov-ernmernt of the state is the police power. This power includes all those general laws and internal regulations necessary to secure the peace, good order» health and prosperity of the people, and the regulation and protection of property rights. Since the police power has never been surrendered to the federal government f the primary responsibility for the protection of the health, welfare and morals of the people remains with the states.

Answer the following questions :
1. Describe the nature of the Confederation that existed in America before the ratification of the Constitution.
2. What are the two doctrines the courts use in defining federal-state relations?
3. What is the preemption doctrine? Where does it derive?
4. What is the abstention doctrine? What is its constitutional basis?
5. What are the factors that have contributed to the extension of federal power?
6. How does economic development affect federal-state relations?
7. What is the interstate commerce clause? In what way has it helped the extension of federal power?
8. Which clause in the constitution is the main source of implied legislative power of Congress?
9. What is police power?
10. Why do we say that the states still have the primary responsibility for the welfare o{ the people?