WASHINGTON — Marijuana would be legal federally in states that already have approved the drug’s use under a bill introduced Thursday by U.S. Sens. Cory Gardner and Elizabeth Warren.

The measure, unveiled at a Capitol Hill news conference, wouldn’t legalize the drug in states that haven’t sanctioned its use or sale.

But in states such as California that have legalized marijuana, it would bring the cannabis industry out of its current financial limbo by giving the industry access to banks and other financial institutions, which previously have been off-limits because of federal prohibitions.

“We just want the federal government to get out of the way,” Warren said.

The alliance between Gardner and Warren represents a bit of a political odd couple, but even the combined effort of a Colorado Republican and Massachusetts Democrat may not be enough to get the legislation through Congress.

Sen. Cory Gardner, R-Colo., speaks during a Senate Judiciary Committee hearing on Capitol Hill, in Washington in 2017. (AP Photo/Alex Brandon, File)

Gardner said the bill had about four or six co-sponsors on the Senate side but admitted that there was a “significant education push we have to do” to garner more support.

The bill represents the latest loop in a roller-coaster relationship Gardner has had with marijuana and the Trump administration since the start of the year.

It started in January when U.S. Attorney General Jeff Sessions rolled back an Obama-era policy that generally left alone states that sanctioned marijuana, which is illegal under federal law.

The move prompted Gardner to use Senate rules to block appointments to the Justice Department for several weeks.

He ultimately relented after he said he received assurances from President Donald Trump that the Justice Department wouldn’t interfere with the marijuana industry.

“President Trump made a commitment to Senator Gardner that he would support a federalist approach to state marijuana laws,” noted Justin Strekal, political director for advocacy group NORML. “Now Congress must do its part and swiftly move forward on this bipartisan legislation.”

The bill is dubbed the Strengthening the Tenth Amendment Through Entrusting States or STATES Act.

Along with guarding states’ right for regulating marijuana, the bill would also remove industrial hemp from the federal Controlled Substances Act, taking the non-psychoactive strain of cannabis used to make fabric, construction materials and more out of the legal gray area that’s held the industry back for decades.

Sen. Elizabeth Warren, D-Mass., is leading the fight for states’ rights to regulate marijuana as they see fit. (AP Photo/Susan Walsh, File)

“The STATES Act is the most significant piece of marijuana-related legislation ever introduced in Congress,” said Don Murphy, conservative outreach director for the advocacy group Marijuana Policy Project. “With its bipartisan backing in the Senate, it symbolically signals the eventual end of marijuana prohibition at the federal level.”

Murphy said his organization is looking forward to the day when cannabis will be fully legalized at the federal level. But in the meantime, he said, they support the states’ right approach in Gardner and Warren’s bill.

Marijuana legalization opponents also noted the significance of the bill.

“While Senator Gardner is calling this a ‘states’ rights’ approach, this bill essentially amounts to the federal legalization of marijuana,” said Kevin Sabet, president of the anti-cannabis group Smart Approaches to Marijuana or SAM. “The bill would shield the pot industry in states that have liberalized their drug policies and prevent the enforcement of federal law. Additionally, the bill would grant marijuana businesses access to the federal banking system, allowing Wall Street investment on an unprecedented scale.”

But many marijuana rights’ activists praised the STATES Act for its social justice components.

“The STATES Act is a first step toward ending the harms of marijuana prohibition,” said Jolene Forman, staff attorney at the Drug Policy Alliance. “This bipartisan proposal clears the way for states to develop their own marijuana policies without fear of federal intervention. This will give states more opportunity to restore communities that have borne the brunt of the drug war and mass criminalization.”

Cannifornian staff contributed to this report.