Yesterday afternoon, White House Press Secretary Sean Spicer suggested that the Justice Department under newly installed Attorney General Jeff Sessions will be more inclined to enforce the federal ban on marijuana in states that have legalized the drug for recreational use. A large majority of Americans, including most Republicans, think that's a bad idea, according to poll numbers released the same day as Spicer's comments.

Answering a question from an Arkansas reporter wondering how the DOJ will respond to that state's new medical marijuana law, Spicer said "there's two distinct issues here: medical marijuana and recreational marijuana." He reiterated President Trump's support for laws that allow patients to use marijuana for symptom relief, which 28 states have enacted. Spicer also noted that Congress has repeatedly approved a spending rider that restrains the DOJ from taking action against medical marijuana suppliers in those states. But he said "there is a big difference between that and recreational marijuana," which eight states have legalized, and predicted there will be "greater enforcement" of the federal ban in those states under Sessions, saying "they are going to continue to enforce the laws on the books with respect to recreational marijuana."

While Spicer emphasized the difference between medical and recreational marijuana, he overlooked a more important distinction: between opposing state laws that allow recreational use of marijuana and supporting federal intervention aimed at overriding them. That distinction is clear in the latest Quinnipiac University poll, which finds that 71 percent of Americans "oppose the government enforcing federal laws against marijuana in states that have already legalized medical or recreational marijuana." By comparison, 59 percent think marijuana "should be made legal in the United States." That means many Americans who oppose legalization nevertheless think states should be free to adopt that policy. A disproportionate number of those people are members of Trump's party: While only 35 percent of Republicans in the Quinnipiac poll supported marijuana legalization, 55 percent opposed federal interference with it.

A CBS News poll conducted last April found even stronger Republican opposition to the sort of meddling Spicer predicted. Asked if "laws regarding whether the use of marijuana is legal" should be "determined by the federal government" or "left to each individual state government to decide," 70 percent of Republicans said the latter, compared to 55 percent of Democrats (who as usual were more likely to favor legalization). These results make sense to the extent that conservatives take seriously their avowed commitment to federalism, which Trump also claims to support. At the 2015 Conservative Political Action Conference, Trump said he favored medical marijuana but had concerns about broader legalization, a decision he nevertheless said should be left to the states. "If they vote for it, they vote for it," he said. Trump confirmed that position at a 2015 rally in Nevada: "In terms of marijuana and legalization, I think that should be a state issue, state by state."

Sessions, a former Alabama senator, also pays lip service to federalism. After the death of William Rehnquist in 2005, Sessions gave a floor speech in which he praised the chief justice for recognizing the limits of federal power:

He understood that the Federal Government, through the Commerce Clause, has broad power, but there are limits to the reach of the Commerce Clause. It does not cover every single matter the United States Senate may desire to legislate on, to the extent that the federal government controls even simple, discreet actions within a State. He reestablished a respect for state law and state sovereignty through a number of his federalism opinions.

In 2013 Sessions cosponsored the Restoring the 10th Amendment Act, which would have facilitated lawsuits by state officials challenging regulations they believe exceed the powers the Constitution grants to the federal government. As the introduction to that bill explained, "The 10th Amendment assures that the people of the United States, and each sovereign State in the Union of States, have, and have always had, rights that the Federal Government may not usurp." But Sessions's support for federalism does not extend to marijuana policy.

During his confirmation hearings, Sessions was hazy on his plans for marijuana enforcement. But he is an old-fashioned drug warrior who complained about the Obama administration's prosecutorial restraint in states that have legalized marijuana, saying "the Department of Justice needs to be clear" that "marijuana is not the kind of thing that ought to be legalized." When the subject is marijuana, it seems, Sessions does not recognize any "limits to the reach of the Commerce Clause."

In that respect Sessions outdoes one of the most famous anti-marijuana crusaders in U.S. history. Harry Anslinger, who ran the Federal Bureau of Narcotics from 1930 to 1962, pushed the states to ban marijuana by claiming the plant turned people into rapists and murderers. Like Sessions, he was not a stickler for facts or logic. But even Anslinger did not go so far as to claim that the federal government had the authority to impose marijuana prohibition on recalcitrant states. "There are no Federal laws on the growth or use of marijuana, the plant being grown so easily that there is almost no interstate commerce in it," The New York Times reported in 1931. "Mr. Anslinger said the government under the Constitution cannot dictate what may be grown within individual States."

The most straightforward way to stop Sessions from cracking down on state-licensed marijuana businesses, assuming Trump does not plan to keep his campaign promise, is for Congress to pass the Respect State Marijuana Laws Act, which Rep. Dana Rohrabacher (R-Calif.) reintroduced a few weeks ago. The bill, which so far has 14 cosponsors, half of them Republicans, would add a single sentence to the Controlled Substances Act: "Notwithstanding any other provision of law, the provisions of this subchapter related to marihuana shall not apply to any person acting in compliance with State laws relating to the production, possession, distribution, dispensation, administration, or delivery of marihuana."

Rohrabacher's bill would not be necessary if federal officials respected the Constitution. But they don't, so it is.