The importance of the Commerce Clause and the jurisdictional power

It is common knowledge that under the American system of federalism, police power gives the states the responsibility for maintaining public order and safety within each state, including the passing and enforcing of criminal laws. However, the federal government must rely on specific powers granted by the Constitution to pass criminal laws. Discuss the importance of the Commerce Clause and the jurisdictional power it grants to the federal government. Include one example of a legal case that was decided based upon the courts application of the Commerce Clause.