Now, in a statement, he says Trump has promised him the Justice Department's new policy wouldn't impact Colorado.
According to White House Legislative Affairs Director Marc Short, Trump "does respect Colorado's right to decide for themselves how to best approach this issue".
News agencies, including the Associated Press and the Los Angeles Times, are reporting that White House spokesperson Sarah Huckabee Sanders has described Gardner's account as accurate and said Trump supports states' rights on the matter. Friday's decision stopped the blockade on the few who were left.
Gardner has been working with other Senators quietly about pushing for a legislative fix that would completely bar the federal government from interfering with states that have legalized marijuana or have voted to do so.
Attorney General Jeff Sessions in January rescinded Obama-era protections that limited federal prosecutions of people in states where marijuana was legal.
Gardner said in a phone call with President Donald Trump Wednesday night, he was promised the DOJ would not target Colorado's legal marijuana industry. In response to that decision, Rep. Gardner had vowed to block all nominees for Justice Department jobs. Under Mr. Sessions's approach, USA attorneys in states where pot is legal were given approval to prosecute cases where they see fit.More news: Breezy Today-Storms Saturday
But Trump has held a sharply different view from Sessions on the issue.
Gardner and others were concerned that it could lead to federal agents taking enforcement actions against dispensaries and other businesses that are legal under Colorado state law.
Cory Gardner, R-Colo., speaks to reporters in the Ohio Clock Corridor after the Senate Republicans' policy lunch on Wednesday, Jan. 17, 2018.
Since January, Gardner has been holding up the approval of around 20 nominees and has treated the issue like a hostage negotiation, agreeing in February to allow a few nominees to be considered as a show of "good faith" to Sessions. "So we're reluctant to reward that sort of behavior".
Maybe we shouldn't get too excited until there's an actual piece of legislation protecting marijuana states.
"My colleagues and I are continuing to work diligently on a bipartisan legislative solution that can pass Congress and head to the President's desk to deliver on his campaign position", he said in the statement.