"I believe in states' rights; and the other day, the president notified me that he would be supporting a states' rights approach when it comes to legalized marijuana", Gardner said on "The Daily Briefing" Friday.
"Because of these commitments, I have informed the Administration that I will be lifting my remaining holds on Department of Justice nominees", Gardner said.
Gardner lifted holds on Assistant Attorney General for National Security, United States Attorneys, and United States Marshals nominees in February as an "act of good faith" after talks with DOJ leadership. Senators press DOJ to stop blocking medical marijuana MORE rescinded an Obama-era policy that paved the way for states to legalize recreational pot.
Bob Ferguson, the Democratic attorney general of Washington state, which permits marijuana use, said Gardner's announcement made him "cautiously optimistic" but until there is a formal agreement or law on the issue he stands ready to defend "Washington's well-regulated marijuana industry".
State Attorney General Bob Ferguson said Friday he is "cautiously optimistic" after President Donald Trump reportedly promised to protect the legal marijuana industry in states, but noted that the president "has demonstrated a willingness to go back on his word".
"Given how much larger the USA cannabis market is in comparison to Canada or any other country this development is potentially game-changing for industry participants", he said in an emailed statement.
One of Gardner's primary points of contention with Sessions' decision to bring the hammer down on states with legal cannabis markets was his assurance during his confirmation hearings that he "would leave states that had legalized marijuana alone".
Democratic US Representative Earl Blumenauer of OR, another state with permissive marijuana laws, expressed skepticism, saying, "Trump changes his mind constantly". In light of Trump's phone call, the senator said he has had a change of heart.
A spokesperson for the White House added that Trump "does respect Colorado's right to decide for themselves how to best approach this issue". But Gardner said Sessions had promised him he'd do nothing to interfere with Colorado's robust marijuana market.
President Trump is going green - and Attorney General Sessions is likely seeing red.
A bill has not been finalized, but Gardner has been talking quietly with other senators about a legislative fix that would, in effect, make clear that the federal government can not interfere with states that have voted to legalize marijuana.
Meanwhile, legislation to protect states where marijuana is legal is still being drafted.
Gardner's office is hopeful of getting enough bipartisan support for the bill to pass the GOP-controlled Congress - something the president's backing would aid.