Attorney General Jeff Sessions drew strong criticism from lawmakers Thursday for changing a Justice Department policy on marijuana enforcement that had allowed states to move forward on legalizing the drug’s recreational and medical use.

Sessions’ move upsets the uneasy status quo between state laws that legalize marijuana and the federal laws against possession and distribution, which was set up by Obama administration guidelines from the Justice Department. Sessions rescinded the Obama guidelines Thursday, which cast uncertainty on what had been a growing pot industry just days after California implemented a recreational pot law.

The DOJ’s policy switch will likely fire up the discussion on marijuana-related legislation. Sen. Kirsten Gillibrand, a New York Democrat, called Thursday for passage of bills to “keep the federal government out of the way when doctors and patients decide that medical marijuana is the best treatment for them.”

Sen. Ron Wyden, the top Democrat on the Finance Committee, said Sessions’ action ignores the will of a majority of Americans and called for a response through a must-pass appropriations bill.

“Any budget deal Congress considers in the coming days must build on current law to prevent the federal government from intruding in state-legal, voter-supported decisions,” the Oregon senator said in a statement.

Watch: Gardner Rails Against Sessions’ Marijuana Action as States’ Rights Issue

The attorney general’s decision prompted Republican Sen. Cory Gardner of Colorado, the first state to legalize recreational marijuana, to hold up confirmation of Justice Department nominees until Sessions sticks to his word given before his confirmation that there would not be a policy change and that President Donald Trump was not looking for one.

Gardner, on the Senate floor, said Sessions’ move was “a complete reversal of what many of us on the Hill were told before the confirmation, what we had continued to believe the last year, and without any notification, conversation, or dialogue with Congress, completely reversed.”

Without the Obama-era guidance, known as the Cole memo, Colorado pot businesses that opened in January 2014 after the state’s voters legalized recreational marijuana are “operating under a cloud of uncertainty” with thousands of jobs and millions of dollars in revenue at risk, Gardner said.

“And certainly, the question of constitutional states’ rights — very much at the core of this discussion,” he said. “Because I believe what happened today was a trampling of Colorado’s rights, its voters.”

Sessions has a history of being tough on drug crimes, and cracking down on crime has been a focus of his tenure as the nation’s top law enforcement official. During his confirmation hearing, he passed on the opportunity to say he would make such a move on marijuana but also pointed out that Congress has outlawed its possession and distribution.

“If that’s something that’s not desired any longer, Congress should pass a law to change — change the rule,” Sessions said at the time. “It’s not so much the attorney general’s job to decide what laws to enforce. We should do our job and enforce laws effectively as we’re able.”

In memo issued Thursday, Sessions said the Obama guidance undermines the rule of law and the ability of law enforcement to enforce existing laws.

“Therefore, today’s memo on federal marijuana enforcement simply directs all U.S. Attorneys to use previously established prosecutorial principles that provide them all the necessary tools to disrupt criminal organizations, tackle the growing drug crisis, and thwart violent crime across our country,” Sessions said.

Reps. Jerrold Nadler of New York, Sheila Jackson Lee of Texas and Steve Cohen of Tennessee, all Democrats on the House Judiciary Committee, said in a statement that they fear the change “will lead to the imposition of harsh criminal penalties on small-time marijuana users who are in compliance with the laws and norms of their states.”

A common theme from Democrats was that the move cuts against the sentiment of the public. Seventy-three percent of voters in a Quinnipiac poll last year said they were opposed to the government enforcing federal laws in states that have legalized medical or recreational marijuana.

“It seems to be the absolute opposite direction from where our country’s headed,” Virginia Sen. Mark Warner said of the Sessions decision.

Aaron Smith, executive director of the National Cannabis Industry Association, remained optimistic. He said rescinding the policy does not necessarily mean that any major change in enforcement policy is on the horizon.

“This has been, and still will be, a matter of prosecutorial discretion,” Smith said. “We therefore hope that Department of Justice officials, including U.S. Attorneys, will continue to uphold President Trump’s campaign promise to not interfere with state cannabis programs, which have been overwhelmingly successful in undercutting the criminal market.”

The assessment from the Marijuana Policy Project, which is focused on ending prohibition, was less rosy. “This extremely misguided action will enable a federal crackdown on states’ rights with regard to marijuana policy,” said Matthew Schweich, the group’s interim executive director. “Attorney General Sessions has decided to use the power of the federal government to attack the ability of states to decide their own laws.”