Attorney General Jeff Sessions has pulled off something that would have been unthinkable just a few years back: he managed to rally Republican lawmakers behind weed.

Sessions announced on Thursday that he would be rescinding a policy from the Obama administration that had discouraged prosecutors in states where marijuana was legalized from bringing charges for marijuana-related crimes, unless they involved distribution to minors, revenue sale benefiting gangs or cartels and a few other federal priorities. In its place, federal prosecutors would be given discretion (not guidance) to pursue marijuana-related prosecutions.

The announcement was a reversal of a memo authored by former Deputy Attorney General James Cole in 2013, who wrote the Obama-era guidelines after Colorado and Washington voted to decriminalize marijuana for recreational use. And it managed to tick off a number of lawmakers from those states as well as the eight others—in addition to Washington D.C.—who have voted to legalize recreational marijuana use since.

Charlie Baker, the Republican Governor of Massachusetts, called the Sessions policy “the wrong decision,” while pledging to “review any potential impacts.” Republican Governor Brian Sandoval of Nevada told The Daily Beast in a statement that he believed “Nevada’s marijuana industry is a model for other states.” Bill Walker, the Independent Governor of Alaska, called the decision “disappointing,” adding that he was “committed to upholding the will of Alaskans on this issue and maintaining our State’s sovereign rights to manage our own affairs while protecting federal interests.” Alaska became the third state to legalize recreational marijuana in 2015.

And on the Hill, Sen. Cory Gardner (R-CO) went a step further saying that he would hold up the confirmation of future Department of Justice staff unless the Sessions policy was changed.

"The decision today blindsided me and many others who were under the belief that this wouldn't happen,” Gardner told reporters. “If the Department of Justice wants another nominee confirmed, they better fix this."

Sessions is a longtime foe of looser marijuana laws and has taken a far stricter and more antiquated approach to combating drug use in general. Though he put on a softer facade in his confirmation hearing, advocates for legalizing marijuana had anticipated that such a decision would come eventually from his office.

But the timing of Thursday’s announcement seemed to catch virtually everyone off guard, contributing to some of the backlash.

Governor John Hickenelooper’s (D-CO) office told The Daily Beast they were given no heads up about the decision. Neither was Governor Jay Inslee (D-WA).

“Not sure what drove the timing on this for today,” a spokesperson for the Washington Democrat told The Daily Beast, adding that they too were just reviewing the memo as soon as the press had seen it.

The Justice Department itself had trouble explaining why Sessions was making his move now and what immediate ramifications there would be for the decision. In a morning teleconference with reporters, a senior DOJ official simply said that “U.S. attorneys offices need to determine what cases need to be brought.” As to whether or not this decision would lead to more marijuana prosecutions, there was no definitive answer.

“I can’t sit here and say whether it will or won’t lead to more marijuana prosecutions,” one of the officials told reporters.

By giving discretion to federal prosecutors, the new DOJ policy could amount to nothing at all. But it sets up a potential battle between states and the federal government. In terms of enforcement, members of state governments were left scrambling as to what would be required of them in coming days and weeks. Others were more adamant about simply ignoring the federal position and preserving their state’s individual laws.

“In California, we decided it was best to regulate, not criminalize, cannabis,” Democratic California Attorney General Xavier Becerra said in a statement to The Daily Beast. “Unlike others, we embrace, not fear, change. After all, this is 2018 not the 20th century.“

U.S. Attorney for the District of Colorado Bob Troyer also issued a statement in which he said that there would be no changes to enforcement in the state as a result of this federal policy shift.

The new policy also comes as commercial marijuana is beginning to boom. Of the eight states that have legalized the drug, six have decided to allow the sale of recreational marijuana. The industry has ballooned in Washington, Oregon, Nevada, Colorado, Alaska and most recently California, where recreational marijuana sales began earlier this week.

“The attorney general of the United States has just delivered an extravagant holiday gift to the drug cartels,” Rep. Dana Rohrabacher (R-CA) said in a blistering statement. “By attacking the will of the American people, who overwhelmingly favor marijuana legalization, Jeff Sessions has shown a preference for allowing all commerce in marijuana to take place in the black market, which will inevitably bring the spike in violence he mistakenly attributes to marijuana itself.”