The selection of U.S. Sen. Jeff Sessions to take over the Justice Department has intensified concerns that the nation’s $6 billion-a-year marijuana industry, riding the momentum of fresh victories in Maine and four other states, may soon run into a powerful new adversary.

President-elect Donald Trump’s recent selection of the Republican senator from Alabama as his attorney general drew immediate expressions of concern from the marijuana industry, which is expected to grow to $7 billion next year.

With the Nov. 8 election, eight states have now declared cannabis legal for adult recreational use. The industry has developed rapidly despite marijuana’s continued status as an illegal substance under federal law. Under President Obama, the Department of Justice has taken a clear position that it would not interfere with states’ decisions to legalize the drug for medicinal or recreational use.

Sessions, however, is considered one of the most outspoken opponents of marijuana legalization in the country and as recently as April criticized the Obama administration for allowing the industry to take root. If he wins Senate confirmation as head of the Justice Department, Sessions would oversee both federal prosecutors and the Drug Enforcement Administration and have the power to make decisions that could halt the rapid growth of the cannabis industry.

“(Sessions) is no friend to marijuana,” said Alysia Melnick, political director for the Yes on 1 campaign, which led the effort to legalize adult-use marijuana in Maine.

Sessions has spoken out against marijuana a number of times, including once saying he was OK with the Ku Klux Klan “until I learned they smoked pot.” He later said he was joking when he made the remark.

At Senate hearings last April, Sessions criticized the Obama administration and marijuana legalization efforts. During a hearing convened by the Senate Caucus on International Narcotics Control, he said, “Good people don’t smoke marijuana.”

“We need grown-ups in Washington to say marijuana is not the kind of thing that ought to be legalized, it ought not to be minimized, that it is in fact a very real danger,” Sessions said in April.

LEPAGE WAITING FOR TRUMP’S CUE

It’s not clear, however, whether Sessions’ stand on marijuana will be tempered by the new president. Trump in the past has said he supports medical marijuana and believes legal marijuana policy should be left to individual states to decide.

The Trump transition team did not respond to requests for comment, and it has not yet declared a clear position on the legalization movement.

Among those waiting for a signal from Trump is Gov. Paul LePage.

LePage opposed the legalization referendum in Maine and said after the election that he would ask Trump about the new administration’s plans before deciding whether to challenge the referendum results in court. LePage’s staff has not responded to requests for comment about any communications with Trump or a potential challenge by the governor.

By the time Trump is inaugurated in late January, one in five adults will live in a state were marijuana is legal.

Maine, Massachusetts, California and Nevada voted Nov. 8 to join Alaska, Colorado, Oregon and Washington as states with legalized recreational marijuana. Arkansas, Florida and North Dakota voted that day to join Maine and 24 other states that already allow the use of medical marijuana.

The Obama administration has issued policy directives – known as the Cole and Ogden memos – that limited federal enforcement of marijuana laws in legalization states, so long as those states took certain steps, such as limiting access to children and preventing marijuana from crossing state lines. However, Sessions, if he becomes attorney general, would not be bound by those directives and could immediately crack down on the marijuana industry.

As attorney general, Sessions could rescind the Cole and Ogden memos, use federal law enforcement power to crack down on the industry and sue states to stop them from enforcing their own marijuana laws. He could direct law enforcement entities to begin criminal crackdowns on existing marijuana businesses, even where state laws have declared it legal.

Legalization advocates say those types of actions would be costly, harm the economy, eliminate thousands of jobs and force the industry back onto the black market.

“Jeff Sessions is a drug war dinosaur, which is the last thing the nation needs now,” said Ethan Nadelmann of the Drug Policy Alliance in a statement. “Those who counted on Donald Trump’s reassurance that marijuana reforms ‘should be a state issue’ will be sorely disappointed.”

A STATES’ RIGHTS MATTER, ADVOCATES SAY

Maine’s marijuana legalization initiative passed by a razor-thin margin and is now awaiting a recount. If the results are upheld, the new law would allow Maine adults 21 and older to possess up to 2½ ounces of marijuana, grow their own plants and buy marijuana at retail stores and social clubs. While use and possession are expected to become legal in January, it will could take a year for the state to establish rules and issue licenses for retail operations.

Melnick said Question 1 supporters are keeping a close eye on the potential impact Sessions could have on Maine’s new law but are also focused on moving forward with implementation.

“We’re hopeful President-elect Trump will respect states’ rights and allow us to implement this law without fear of federal interference. He has expressed support for states making decisions about marijuana,” she said. “Our hope is that his appointee would come in line with that approach.”

The Marijuana Policy Project – which has backed legalization efforts in Maine and other states – released a statement following Trump’s announcement that emphasizes the president-elect’s past statements on legal marijuana. The organization called on Trump to recognize the “growing sentiment” across the country that the federal government should not waste tax dollars on enforcing marijuana prohibition laws.

“President-elect Trump has said on multiple occasions that he respects states’ right to establish their own marijuana policies,” the MPP statement said. “We would expect appointees who serve at the pleasure of the president to stick to the president’s position on this subject. It would certainly be controversial if Sen. Sessions defied the president who appointed him.”

Aaron Smith, executive director of the National Cannabis Industry Association, also emphasized Sessions’ support for states’ rights when reacting to Trump’s nomination.

“Voters in 28 states have chosen programs that shift cannabis from the criminal market to highly regulated, tax-paying businesses. Sen. Sessions has long advocated for state sovereignty and we look forward to working with him to ensure that states’ rights and voter choices are respected,” Smith said in a statement.

Not everyone connected with Trump’s transition team and administration is anti-marijuana.

Venture capitalist and PayPal founder Peter Thiel, known for investing in the cannabis industry, has joined Trump’s transition team. Founders Fund, an investment firm created by Thiel, in 2015 joined a $75 million funding round for Privateer Holdings, whose subsidiary sells marijuana under the brand name Marley Natural.