Drug reform advocates are voicing cautious optimism after new leadership of the nation's top drug enforcement body signaled a rerouting of policies away from marijuana and onto more serious drugs.

Chuck Rosenberg, who was just appointed head of the Drug Enforcement Agency (DEA), was previously chief of staff to FBI Director James B. Comey, and has spent his career in various capacities of law enforcement. Despite this, activists say they see no indication that Rosenberg will be as hawkish on marijuana as his predecessor, former director Michele Leonhart, who was forced to resign last month amid controversy surrounding widespread agency misconduct.

"While we don't yet know a lot about Rosenberg's views on marijuana or respecting state legalization laws, it'd be shocking if he turned out to be even less friendly to reform than Michele Leonhart was," Tom Angell, chairman of the Marijuana Majority, told ATTN: in an email. "If and when Rosenberg is formally nominated for the administrator job he's going to face tough questions from members of Congress who represent legalization states and who will want to know whether he intends to spend federal resources undermining the will of their constituents."

The appointment by newly-minted Attorney General Loretta Lynch earlier this month comes after Leonhart stepped down in response to allegations that DEA agents misused federal monies and threw wild, so-called sex parties with hired prostitutes. Her resignation also came after accusations of defying administration stances on marijuana. "She was an insubordinate to the president when she criticized his acknowledgement of the fact that marijuana is 'no more harmful than alcohol,'" Rep. Steven Cohen (D-Tenn.) wrote in a statement last month.

The Obama administration has signaled that drug laws, especially marijuana laws, are due for an overhaul, or at least a review. Under his presidency, numerous states have been allowed to experiment with legal medical and recreational use, even though the federal government still considers marijuana a Schedule 1 substance alongside heroin––in other words, a drug with no potential for medical use. That discrepancy has caused frustration over DEA raids on business operating legally under state laws, but not under federal ones. Adherence to that classification also defined the hard-line stance on marijuana that characterized Leonhart's tenure at DEA, where she championed "mindset straight out of the 1930s," according to Dan Riffle of the Marijuana Policy Project.

But that could all change, according to some observers. According to an unnamed senior administration official quoted in the LA Times, Rosenberg is expected to focus DEA attention away from marijuana, pivoting more heavily towards drugs like heroin, and even modernize DEA's protocol for "classifying, declassifying and reclassifying drugs."

If those predictions materialize, it could mean an agency vastly different from the one under Leonhart's leadership, which often clashed with the Obama administration on drug policy. "[Leonhart] has been really at the core of so much destruction in our eyes over the years," Steph Shere, executive director of Americans for Safe Access told ATTN: last month. She "led the war on patients under Bush and some of the beginning years under Obama, and was a key obstructionist for the rescheduling of cannabis," according to Sherer

Looking at his resume, it's difficult to gauge how Rosenberg will shape the DEA in the coming months. He served in top administrative positions at the Department of Justice, and worked as chief of staff to the deputy attorney general, counselor to former Attorney Gen. John Ashcroft, counsel to former FBI director Robert Mueller, and was a U.S. attorney in Virginia, and a DOJ tax prosecutor, according to the LA Times.

Rosenberg is expected to remain at the DEA's helm for the rest of Obama's term, but even as acting administrator, he has the ability to shake things up. The position allows the appointee to steer enforcement actions, and also weigh in on the rescheduling of drugs, which could ultimately mean big changes for both marijuana businesses, and researchers looking into the plants medical potential. Over the years, the DEA, which controls the amount of pot approved for research, has repeatedly denied petitions seeking administrative change, according to US News.

While Rosenberg's pending appointment could mean big changes in the way the federal government handles marijuana, some observers see his presence as a potential harbinger of even bigger changes.

"People in our movement have been saying that it doesn't necessarily make sense to have DEA as a separate agency, and that maybe it should be folded into the FBI," According to Angell of the Marijuana Majority. "Perhaps President Obama agrees, and appointing a top bureau official to oversee the drug agency could be the first step in such a merger."