The U.S. Department of Justice decision to rescind Obama-era guidance on marijuana enforcement elicited furious statements from lawmakers on both sides of the aisle.

Attorney General Jeff Sessions gave federal prosecutors the green light to enforce federal marijuana laws in states where cannabis has been legalized in some form. In a statement, Sessions — a longtime opponent of legalization — said the Obama-era memos that directed prosecutors not to interfere with state activities when it came to legal pot undermined the rule of law.

Responses from Senators on Capitol Hill came swiftly. At least one Senator, Republican Cory Gardner of Colorado, threatened to hold up judicial nominations until the decision was reversed. Another questioned how the Justice Department could justify allocating resources to go after legal users when there are other pressing issues to address. And at least one expressed hope that this action would push Congress to ultimately legalize cannabis.

Gardner was among the Senators who were most alarmed by the Attorney General’s actions, since recreational marijuana has been sold legally in Colorado since 2014. He told reporters he was “blindsided” by the move on his way to deliver a blistering speech on the Senate floor.

“Perhaps the Department of Justice didn’t think this would be a big deal,” Gardner said on the floor. “I believe what happened today was a trampling of Colorado’s rights, its voters.”

Gardner has made clear that he did not support legalization, but he does respect the will of Colorado’s voters who chose to permit the sale and use of marijuana for recreational purposes in 2012. He said Thursday that before voting to confirm Sessions he had been assured that as Attorney General he would not make marijuana a priority. On the floor of the Senate, Gardner called on Sessions to explain his decision making and to reverse the Thursday decision.

“Until that happens, I think I am obligated by the people of Colorado to take all steps necessary to protect the state of Colorado and their rights,” Gardner said. “And that’s why I will be putting today a hold on every single nomination from the Department of Justice.”

Vermont Democrat Sen. Patrick Leahy, a member of the Senate Judiciary Committee who has repeatedly pressed Sessions about marijuana policy. On Thursday, he offered a sarcastic assessment of the decision in response to a question from TIME.

“Well, you know, it’s interesting. The Justice Department doesn’t have enough people to go after the opioid crisis that’s killing people. We don’t have enough people to go after Russian hackers and Korean hackers,” Leahy said. “But, by golly, you got some grandmother smoking a marijuana cigarette in a state where it’s legal, we’ve got to go after that.”

While Thursday’s decision came as a shock to some, Attorney General Jeff Sessions has lucidly expressed opposition to marijuana throughout his career. He reportedly said that he thought the Ku Klux Klan was “okay until I found out they smoked pot,” back when he was a U.S. Attorney. At a hearing in April 2016, when he was still a Senator, Sessions said cannabis is “a very real danger” and that “good people do not smoke marijuana.” Speaking to law enforcement in March, the Attorney General said that marijuana is “only slightly less awful” than heroin.

“I reject the idea that America will be a better place if marijuana is sold in every corner store,” Sessions said at the time. “Our nation needs to say clearly once again that using drugs will destroy your life.”

President Donald Trump’s stance on legal pot is more of a mystery, but he did tell a Colorado television station that he thinks the issue should be left up to the states during the 2016 campaign, according to the Denver Post.

Democratic Sen. Mark Warner of Virginia said Thursday that Sessions’ move shows how out-of-step the administration is when compared to red and blue states across the country. “For folks who always advocated states rights and the 10th amendment, it seems pretty counter to that core belief,” he said.

In 29 states and D.C., marijuana is legal in some form, including California where recreational use was officially legalized on New Year’s Day. In Colorado, marijuana is big business. The state reported over $1 billion in medical and recreational marijuana sales in both 2016 and 2017.

Republican Sen. Dean Heller of Nevada, where legal pot shops have been open for business since summer 2017, called on the Department of Justice to work with his state on the issue.

“Knowing Attorney General Sessions’ deference to states’ rights, I strongly encourage the DOJ to meet with Governor Sandoval and Attorney General Laxalt to discuss the implications of changes to federal marijuana enforcement policy,” Heller said in a statement, according to the Washington Post. “I also urge the DOJ to work with the congressional delegations from states like Nevada that have legalized marijuana as they review and navigate the new policy.”

Sen. Cory Booker, a Democrat from New Jersey, said he wasn’t surprised by the Thursday move given Sessions’ history and his efforts to block him from becoming Attorney General. Still, in an interview outside of his Senate office, he called Sessions’s actions “outrage” and an attempt to “restart the War on Drugs” that has “cost the country trillions of dollars, so many lives, and economic devastation.”

“This is why you see lots of states, red and blue states, moving on legalization of medical marijuana or legalization of recreational marijuana, to stop this craven injustice in our country,” he said.

Booker said he hopes the action pushes his colleagues to support legislation he’s introduced that would legalize marijuana.

“For us to have this crisis now is, to me, really forcing a moment where this country has to decide where we’re going to go,” he said. “We have the power here in Congress to stop this Attorney General from what I believe is a rogue throwback to a failed war on drugs that’s going to endanger many, many Americans, families, and communities.”

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