contentious legislative process. An example is the decriminalization of marijuana in Washington, Oregon, 
Colorado, and Alaska. 
States’ Authority to Pass Criminal Laws 
States are sovereign and autonomous, and unless the Constitution takes away state power, the states have 
broad authority to regulate activity within the state. Most criminal laws at the state level are derived from 
the states’ general police powers, or authority, to make and enforce criminal law within their geographic 
boundaries. Police power is the power to control any harmful act that may affect the general well being 
of citizens within the geographical jurisdiction of the state. A state code, or state statutes, may regulate any 
harmful activity done in the state or whose harm occurs within the state. 
Congress’s Authority to Pass Laws 
Federal lawmakers do not possess police power. Instead, Congress must draw its authority to enact 
criminal statutes from particular legislative powers and responsibilities assigned to it in the Constitution. 
Congress’s legislative authority may be either enumerated in the Constitution or implied from its provisions, 
but if Congress cannot tie its exercise of authority to one of those powers, the legislation may be declared 
invalid. 
Enumerated powers, for example, the power to regulate interstate commerce, are those that are specifically 
mentioned in Article I Section 8 of the Constitution. Over the years, however, courts have broadly 
interpreted the term “interstate commerce” to mean more than just goods and services traveling between 
and among the states. Instead, interstate commerce includes any activity—including purely local or intrastate 
activity—that affects interstate commerce. The affectation doctrine maintains that congressional authority 
includes the right to regulate all matters having a close and substantial relation to interstate commerce. 
Although the Court has found limits on what affects interstate commerce, Congress has used its broad power 
to regulate interstate commerce to criminalize a wide range of offenses including carjacking, kidnapping, 
wire fraud, and a variety of environmental crimes. 
The implied powers of Congress are those that are deemed to be necessary and proper for carrying out 
all the enumerated powers. Article I Section 8 of the Constitution states, “Congress shall have Power . . 
. to make laws which shall be necessary and proper for carrying into Execution the foregoing Powers, 
and all other Powers vested by this Constitution.” The implied powers doctrine expands legislative power 
of Congress, and for that reason, the Necessary and Proper Clause has often been called the “expansion 
clause.” Due to the implied powers found in the Necessary and Proper Clause, Congress has authority to pass 
legislation and regulate a wide variety of activity to the extent that it is able to show that the law furthers one 
of the enumerated powers. Nevertheless, the Court will overturn acts of Congress when it believes Congress 
has overstepped its constitutional authority. So, despite the broad expanse of implied powers, Congress’s 
authority is still limited and by no means is as vast as the states’ police powers. 
Conflicting State and Federal Statutes 
Sometimes substantive federal law conflicts with state laws or policies, and sometimes the federal 
government’s interest in prosecuting cases in federal court conflicts with competing interests of the states. 
One recent conflict between federal interests and state interests involves Oregon’s physician-assisted suicide 
law, the “Death with Dignity Act”. See, Gonzales v. Oregon, 646 U.S. 243 (2006)(upholding Oregon’s law 
Introduction to the American Criminal Justice System
101