Kevin Sabet, who worked in the ONDCP in the three previous presidential administrations and now leads a group, Smart Approaches on Marijuana, which opposes pot legalization, told Politico that the move "reduces the prominence of these programs and puts them in the bowels of agencies that have different priorities."

Having the relatively small ONDCP located in the White House "elevates the importance" of the combat against substance abuse, added Sabet.

During his campaign for president, Trump promised to both crack down on drug trafficking and invest heavily in treatment efforts.

"We're going to take all of these kids — and people, not just kids — that are totally addicted and they can't break it," he said at an Ohio campaign event in 2016. "We're going to work with them, we're going to spend the money, we're going to get that habit broken."

Sen. Shelley Moore Capito, R-W.Va., whose opioid-ravaged state provided Trump the largest margin of victory of any in 2016, said she would oppose the proposal, emphasizing the importance of keeping the two programs "under the president's purview."

Trump may have some support, however, from those who view the ONDCP as an extension of a failed war on drugs. When the president proposed the same cut to the office last year, Grant Smith, deputy director of the Drug Policy Alliance, called the two grants " a phenomenal waste of money that contribute to the incarceration and stigmatization of drug users."

That's not to say that the Trump administration is allying with groups interested in ending the drug war. Attorney General Jeff Sessions has prompted bipartisan outrage by signaling that the Department of Justice may prosecute marijuana growers in states that legalized pot, a reversal of Obama's approach.