President Donald Trump said Friday he will “probably” support a bill that would permit states to set their own marijuana policies, removing the threat of federal prosecution from marijuana growers, sellers, and consumers in states that have decriminalized cannabis to one degree or another.

Just before leaving for the G-7 summit in Canada, Trump was asked about the bill, which had been introduced in Congress the day before by, among others, Senator Cory Gardner (R-Colo.).

“I support Senator Gardner,” Trump replied. “I know exactly what he’s doing. We’re looking at it. But I probably will end up supporting that, yes.”

The Trump administration’s inconsistent policy with regard to state marijuana laws was one impetus for the legislation. As a candidate for president, Trump said he favored leaving marijuana policy up to the states. In the administration’s early months, Attorney General Jeff Sessions strongly suggested that he would not prosecute anyone violating federal marijuana law in states that had relaxed their own laws, continuing a Justice Department policy that had been in place since 2013. Gardner claims to have been the personal recipient of such assurances and was “enraged” when Sessions reversed course in January, according to the Los Angeles Times. Trump later reinstated the hands-off policy without consulting Sessions.

According to a press release Gardner issued Thursday, 46 states plus Washington, D.C., Puerto Rico, Guam, and a number of American Indian tribes have relaxed their marijuana laws in recent years, some permitting pot strictly for medical reasons and others allowing it for recreational purposes. The conflict between these laws and federal laws has several serious consequences, said the release:

Legitimate businesses that comply with state laws are blocked from access to basic banking services. Illicit markets often spring up and local law enforcement must divert resources needed elsewhere. Thousands of people are prosecuted and locked up in our criminal justice system. Qualified scientists and state public health departments struggle to conduct basic and epidemiological research or spur medical advances, and the fundamental nature of state and tribal sovereignty is violated.

It is significant that Gardner is, as the Times put it, “framing the issue as one of state’s [sic] rights.” The bill’s title is the Strengthening the Tenth Amendment Through Entrusting States (STATES) Act. The 10th Amendment declares that any powers not delegated to the federal government by the Constitution are reserved to the states or the people. Since controlling substances is not a power delegated to the federal government, it follows that states are free to establish their own drug policies. Some may go the route of complete prohibition; others, of partial or total legalization. As Gardner explained in a tweet, “Our bill does not legalize marijuana. Instead, it allows the principle of federalism to prevail as the founding fathers intended and leaves the marijuana question up to the states.”

Gardner seems particularly concerned that federal cannabis prohibition inhibits the growth of the marijuana business in states where it is legal. At a Thursday press conference, he said, “If you are in the marijuana business … you can’t get a bank loan or set up a bank account because of concern over the conflict between state and federal law. We need to fix this. It is time we take this industry out of the shadows, bring these dollars out of the shadows.”

The STATES Act would rectify this by not only repealing the federal marijuana ban but also explicitly stating that “compliant transactions are not trafficking and do not result in proceeds of an unlawful transaction,” according to Gardner’s press release.

The bill “faces tremendous head winds” in Congress, John Hudak, a marijuana policy expert at the Brookings Institution, told the Times. Congress has been slow to respond to the sea change in public opinion vis-à-vis marijuana, and even Trump’s remarks may not make much difference.

“We have seen this president voice his support for a lot of things related to cannabis, but he has done absolutely nothing to move legislation,” said Hudak. “This is just more empty rhetoric from a president who is vague on this issue.”

Only time will tell whether Trump remains true to his word or is — if you’ll pardon the expression — just blowing smoke.