Societal morality issues are very important, but they are issues that government has shown itself to be spectacularly incompetent at dealing with. And if government is granted the power to impose societal morality rules, there is no guarantee that it will be your preferred rules which will be imposed. Certainly the evidence from recent decades is that government will instead impose rules you personally are likely to detest.
Instilling and inspiring proper moral values is the perview of parents and family and friends and churches and any number of other voluntary organizations and associations, but not government. [Especially not government-run schools, which have tended to shred and destroy proper moral values, but then that's another rant...] The Drug War has exascerbated these problems by creating enormous financial incentives to break the law (just as Prohibition did), by corrupting our judicial system and law-enforcement agencies, and by trashing the Constitution and the principles of a free society upon which this nation was founded.
The most moral thing we can do is end the Drug War, and thereby end this cancer that has been eating into our society and corrupting our government.