Under Review

Note Many new Texas laws took effect on September 1st, 2025. We are working on reviewing this page and making updates if needed. However, information may be out of date until our review is complete. For help locating current laws, ask a librarian.

The Supremacy Clause

What does it mean if something is legal under state law but illegal under federal law? The links below explain the relationship between state and federal law in general terms, as well as how it applies to cannabis laws.

Understanding the Law

What happens when a state law contradicts a U.S. federal law?
This brief article explains the Supremacy Clause of the United States Constitution and how it affects the discrepancy between cannabis laws at the state and federal levels.
The Heritage Guide to the Constitution - Supremacy Clause
This essay from Professor Gary Lawson explains the history and significance of the Supremacy Clause of the United States Constitution.
State Marijuana Laws at Odds with Federal Enforcement
Stanford Law Professor Robert MacCoun discusses the Department of Justice memos regarding the enforcement of marijuana laws and explains what they mean in easy-to-understand terms.

Federal Guidance

The federal government has issued statements regarding enforcement efforts.

Understanding the Law

Presidential Pardon for Federal Marijuana Offenses
In December 2023, President Biden issued a blanket pardon for "simple possession of marijuana, attempted simple possession of marijuana, or use of marijuana in violation of the Federal and D.C. laws."
Justice Department Issues Memo on Marijuana Enforcement
In 2018, the Department of Justice issued a statement rescinding the previous DOJ memo which established guidelines for the the federal marijuana enforcement policy. This memorandum requires U.S. Attorneys to enforce the laws enacted by Congress, a departure from the previous policy that enumerated enforcement priorities but required stringent regulation from states that legalized cannabis use.
Justice Department Announces Update to Marijuana Enforcement Policy
In light of the decriminalization of marijuana in some states, the Department of Justice issued a statement in 2013, often referred to as "the Cole memo," clarifying their approach to enforcement. In this statement, they identify several enforcement areas that federal law enforcement will continue to pursue, while making it clear that states in which cannabis use is legal are responsible for establishing strict regulatory systems.
What Can I Bring: Medical Marijuana
The Transportation Security Administration recently updated its policy regarding screening procedures. Safety, rather than searches for illegal drugs, is their priority, but they will refer criminal violations to law enforcement.

Note The library cannot tell you what the law means for your situation.

Texas State
Law Library

Cannabis & the Law

Under Review

The Supremacy Clause

Understanding the Law

Federal Guidance

Understanding the Law