Trump has decided that legalization of marijuana, just like pretty much all the other progress we've made over the last 8 years, is a no-go. Gotta make sure those privatized prisons are meeting their minimum occupancy quotas, after all. Can't let that totally unjustifiable source of income die, even though legal marijuana would make significantly more money.
Fun fact: Legal marijuana sales totaled $6.7 billion, last year.