He actually started the reschedule process in 2022, but before that there were attempts by dems to do legalization via legislation but in the senate that didn’t end up getting enough votes.
Rescheduling via legislation is more direct and skips the lengthy process describe in the law for executive action. The president is not able to immediately snap their fingers and reschedule. People within the DEA / other agencies have showed it down since 2022. It’s at the last stages now after the public comment hearing in December. For what it’s worth, as VP Harris did try to call on the agencies to speed up said process but she has no direct power to do so
Ah, the article linked above seemed to say that he’d just begun the process this past May, but maybe I misread it. I will read it again.,
The part that happened in May was the actual rule being formally proposed.
It [the formal rule proposal] is the next step in the rescheduling process begun by Biden in October 2022, and follows a recommendation by the Department of Health and Human Services in August to reclassify marijuana.
https://www.politico.com/news/2024/05/16/biden-announces-marijuana-reclassification-00158408