Well, even in the absence of more substantive action, browbeating Congress to lift the prohibition on federal enforcement that (on its face, though the Administration has implied that it views it as unconstitutional) interferes medical cannabis laws.
Sessions is, after a year in office, looking "very hard right now" at marijuana enforcement policy, which is bureaucratese for "don't hold your breath". He also said he thought the idea some people have put forward suggesting legal pot would solve the heroin problem is stupid. And... he's right. That is stupid.
He hasn't done anything, even things that were in his power to do.
