And yet Jeff Sessions, Trump's nominee for Attorney General, is one of the most notorious anti-drug (particularly anti-pot) politicians around: http://www.csmonitor.com/USA/Justice/2016/1122/As-Trump-s-AG...
I'd wager a guess Trump snorted his share of blow in the 1980s, but congressional republicans and the private prison industry are going to be calling the shots on the drug war for the next 4 years.
Which is an issue considering the lobbying the businesses do [2] - they are very much invested in keeping their businesses going and keeping folks in jail.
[1] https://www.prisonpolicy.org/reports/pie.html [2]https://en.wikipedia.org/wiki/Private_prison#Lobbying