U.S. Rep. Earl Blumenauer (D-Ore.) introduced a bill with three other members of Congress to formalize protections for states that have legalized the cultivation, sale and use of cannabis.

The Oregon representative proposed the bill with bi-partisan co-sponsors Sen. Elizabeth Warren (D-Mass.), Sen.  Cory Gardner (R-Colo.) and Rep. David Joyce (R-Ohio).

Rep. Earl Blumenauer (Henry Cromett)
Rep. Earl Blumenauer (Henry Cromett)

The Strengthening the Tenth Amendment Through Entrusting States Act, or STATES Act, would resolve some of the legal uncertainty created when U.S. Attorney General Jeff Sessions revoked the Cole Memo in January. The Cole Memo was an Obama-era Justice Department letter that formalized the federal government's commitment to staying out of state-regulated weed industries.

The STATES Act would amend the Controlled Substances Act so that its rules no longer applied to states with legalized cannabis industries, and would ensure that states where legal weed businesses followed basic rules would not face interference from federal law-enforcement agencies. It would also remove industrial hemp from the list of controlled substances.

"For too long the senseless prohibition of marijuana has devastated communities, disproportionately impacting poor Americans and communities of color. Not to mention, it's also wasted resources and stifled critical medical research," Blumenauer said in a statement announcing the bill. "It's past time to put the power back in the hands of the people. Congress must right this wrong."

The bill would set the legal age of cannabis-use at 21, with an exception for medical use. The proposed law change would bar cannabis companies from employing anyone under 18. It would also bar the sale of weed at truck stops and rest areas.