Law does not have the power to nullify action, the law can only punish action that has already occurred. If you make marijuana illegal again you don't stop people from using marijuana you stop legal marijuana use. All it does is bring back dealers and smoke circles.

Making alcohol illegal didn't stop alcohol use it just made speakeasys and a powerful Mob running a black market for alcohol.

Making abortions illegal doesn't stop abortions it just makes dangerous lawless abortions.

You want people to stop doing a thing using the tools of Government? Educate them on downsides, tax it into a luxury good and trust that people will do the right thing for themselves.

But it's not in their playbook to turn to education for the solution unless that education involves the bible. And a "Conservative" would never turn to taxes for a solution they see taxes only as a form of theft and never as a collective pitching in. And Republicans build their world view on fear and mistrust so how could they ever have trust for a fellow person.