Yes, it did work for Portugal. Portugal does not have the pharmaceutical industry that the US does.
Due to criminalization of certain drugs and the extreme enforcement thereof demand for legally available drugs has never been higher in the US. The pharmaceutical industry is more than happy to fill that gap and meet the economic demand. By ignoring the data and eliminating access to controlled substances demand has not diminished but instead shifted to alternate products.
Criminalization/legalization ignores all the data and research on this problem.
The argument is that people are going for legal more potent, more dangerous drugs in US because much harmless marijuana is illegal (Just as when alcohol was prohibited
people switched from wine and beer to moonshine). This is true everywhere including US. Not just Portugal. So when relatively harmless recreational drugs are decriminalized, people won't go for fentanyl or oxy.
Then of course we have the moral argument. The addicts are an extremely at risk, isolated, poor community. They can't seek help as their very existence is illegal (they consume illegal drugs). If drugs were legal, they could seek help without fear or stigma, others could help them without fearing breaking law, NGOs could legally operate in this domain helping them (with disposable needles, safe usage etc.. not just in rehabilitation). All this is true for US. Not just Portugal.
> The argument is that people are going for legal more potent, more dangerous drugs in US because much harmless marijuana is illegal
I'd argue that there is demand for mind-altering substances in the US because of societal reasons. I count marijuana in there because I don't think any other country in the world has made a bigger deal of it than the US. It is a part of pop culture in a way that doesn't happen anywhere else in the world to my knowledge.
No judgment implied on people who use marijuana, of course.
Criminalization/legalization alone does not curb demand for health damaging drugs. The only important goal in talking about drugs is reducing intake to increase personal health. Everything else is either a beneficial byproduct of that goal (crime, dependency, disease) or an antithetical motive.
Marijuana availability would not increase personal health and there is no indication persons consuming legally prescribed opioids would prefer legal and unprescribed marijuana alternatively merely because it is less unhealthy. You can legalize or criminalize all of it, but either way demand for consumption will continue to increase in the US according to the data available.
Due to criminalization of certain drugs and the extreme enforcement thereof demand for legally available drugs has never been higher in the US. The pharmaceutical industry is more than happy to fill that gap and meet the economic demand. By ignoring the data and eliminating access to controlled substances demand has not diminished but instead shifted to alternate products.
Criminalization/legalization ignores all the data and research on this problem.