The U.S. attorney general could decide tomorrow to begin a legal assault on state-regulated marijuana sales, and federal judges likely would rule in the Justice Department's favor.

But reform advocates aren’t afraid attorney general nominee Loretta Lynch would do that, even if she personally opposes pot legalization.

Lynch said she opposes legal sales of marijuana Wednesday during a Senate confirmation hearing in which she also said she disagrees with President Barack Obama about the harmfulness of the drug.

Obama told The New Yorker last year drinking alcohol is more dangerous than smoking pot, and he said “it’s important" for voter-approved legalization to proceed in Colorado and Washington state.

Lynch, a federal prosecutor based in New York, said, “I certainly don’t hold that view and don’t agree with that view of marijuana. I certainly think the president was speaking from his personal experience and personal opinion, neither of which I’m able to share.”

Continuing, she said, “I can tell you that not only do I not support the legalization of marijuana, it is not the position of the Department of Justice currently to support the legalization. Nor would it be the position should I become confirmed as attorney general.”

Attorney general nominee Loretta Lynch testifies during her confirmation hearing in the Senate Judiciary Committee on Wednesday.

J. Scott Applewhite/AP

Though seemingly entrenched and broadly supported, state marijuana regulations are legally fragile, as possession of the drug for any reason – outside limited research – remains a federal crime.

Outgoing Attorney General Eric Holder has allowed states to regulate and tax sales of pot for recreational use, saying in 2013 states could proceed so long as certain enforcement priorities weren't affected. But future attorneys general conceivably could bring legal sales to a screeching halt.

Lynch did not commit to changing existing department policies, but Sen. Jeff Sessions, R-Ala., appreciated the candid response and told her, “I hope that you will cease to be silent."

At the same hearing, Lynch carefully responded to questions from Sen. Lindsey Graham, R-S.C., saying it “certainly would be my policy if confirmed as attorney general to continue enforcing the marijuana laws,” with a focus on violations of enforcement priorities already outlined by the department, such as marijuana being transported from states that allow recreational use to those that do not.

Anti-legalization activists were tickled to learn of a potentially powerful ally.

"We are breathing a sigh of relief," Kevin Sabet, president of the anti-legalization group Smart Approaches to Marijuana, said in an email blast. "Ms. Lynch is a knowledgeable, experienced, justice-minded individual, and for her to come out so adamantly against legalization is extremely encouraging. It will give our efforts a shot in the arm."

Lynch’s disagreement with Obama on marijuana in some ways mirrors disagreement expressed by Drug Enforcement Administrator Michele Leonhart. Pro-legalization reformers who demanded the ouster of Leonhart for insubordination, however, aren’t particularly alarmed by Lynch’s comments.

“We can only hope she was telling some lawmakers what they need to hear in order to get through the confirmation process,” says Mason Tvert, a spokesman for the Marijuana Policy Project.

“It would be shocking if she is actually unaware that marijuana is far less harmful than alcohol,” Tvert says. “The CDC attributes tens of thousands of deaths each year to alcohol use alone, including hundreds from overdose, whereas no deaths are attributed solely to marijuana use and there’s never been a fatal overdose.”

Tom Angell, chairman of the group Marijuana Majority, is likewise far from panic.

"We don't need federal officials to personally support legalization,” he says. “We only need them to respect the will of voters who have implemented legalization in their own states.”

Angell says he heard in Lynch’s testimony a willingness to respect state marijuana laws. “As long as they don't spend resources trying to overturn those duly-enacted laws, I'm much less concerned about the personal views of Justice Department personnel,” he says.

There was similarly muted reaction from congressional leaders who favor marijuana reform.

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Rep. Dana Rohrabacher, R-Calif., declined to take a whack at Lynch, merely responding to her comments in an emailed statement by saying "there are dangers in consuming marijuana, alcohol and soda pop," and that it's his opinion the cost of regulating people's choices "far outweighs the benefits."