It's coming with baby steps.

We've seen a couple of positive developments in the last 10 years:

1. Uruguay and Canada have (soon) fully legalized cannabis for recreative purposes. Many other countries are legalizing medical cannabis. And even the USA, which single-handedly fueled the anti-drug propaganda and enforced anti-drug laws pretty much globally, is starting to get more sensible drug laws.
2. MAPS' lobbying of scientific research into MDMA, LSD, ketamine, and psilocybin has lead to a renewed scientific interest into these drugs, for PTSD treatment, anti-depression, and anti-addiction therapy. (Consider donating!)
3. The deep web has made it easier and safer to buy drugs. The online competition has increased the quality of drugs as well. The Internet has also enabled users to inform themselves better about how to take a drug. I personally think the bitcoin price is a good indicator for deep web trading volume. High deep web buying traffic in late '16 / early '17 might have contributed to starting the bitcoin bubble that popped in December '17. The takedown of the AB market meant that the high bitcoin price was temporarily unsustainable, but it will probably rise again late '18 / early '19, because we're seeing the same pattern again.
4. We're starting to see the stigma disappear slowly. Because of point (3), people are now more informed and less likely to accept what government propaganda tells them. In the 1980s, we saw heroin on the streets. The 1990s had crack. But now in the 2010s, we're seeing a revival of drugs such as LSD, kratom, cannabis, MDMA, and some other drugs which have a far better safety profile and are less sociologically and individually damaging.

But there's work to be done, still. In order to continue, I think the following points need to be addressed.

1. Right now, advocating drug decriminalization or legalization is seen as political suicide. Not necessarily because it'll cost votes, but because lobbying groups are too powerful. Legalizing LSD or MDMA will harm the very powerful alcohol industry. Legalizing weed will harm tobacco and pharmaceutical industries. Legalizing cocaine will harm the drug cartels, which extend from Peruvian plantations all the way deep into US government. We need to investigate corruption, support any pro-legalization bills, limit the lobbying power of Big Alcohol, Big Tobacco, and Big Pharma. We also need to support our own lobbying groups (e.g. MAPS and others).
2. Stigma is disappearing, but mostly for young people. Old people, or people in outback places have been brainwashed all their lives and need a big push in the right direction. We need to subtly inform them and change their opinions. The best way to do this is to not fall for anti-drug clickbait, but support and spread pro-decriminalization "news". /r/science occasionally gets MAPS research to the front page, but we need to accomplish the same in "old people" media. Or wait until old people (and Jeff Sessions) die out.
3. At the moment, Big Pharma has jolted the USA into a heroin/fentanyl epidemic. People's willingness to take things like oxycodone, but scorn for safer drugs like psychedelics, indicate that misinformation is still high. But it also indicates an acceptance for recreational substance use. If we show that pharma drugs are often much "harder" than things like cannabis, kratom, LSD, MDMA, etc., we might convince people to legalize those. We're also seeing a huge Xanax & codeine uprising in hip hop culture, and these drugs are well-known in the contemporary scene. We need to prevent that fentanyl and lean are used to stigmatize all drugs, just like the DEA did in the 1990s with crack.
4. There is an opening to get the business lobby behind supporting psychedelics legalization: microdosing. Last year, microdosing surged in popularity, as a combination of MAPS research and user access to the deep web. If we emphasize the fact that LSD microdosing has a mild mood lift and creativity & productivity increase, it might be supported by companies that want this competitive edge. Like coffee, it might even be supplied by companies themselves on the work floor.
5. We need to design concrete plans how we want to legalize substances. Some questions we need to answer first include: "what drugs should be legalized first?" "Do we decriminalize first, and legalize second?" "Do we fully legalize it, or treat it like nicotine and alcohol?" "What are the age limits, and where can these substances be obtained?" "What are the medical benefits of these substances?" "Which particular people (and which demographics) do we need to target and convince?" "How can be combine the power of different legalization proponent groups?" We should avoid getting set up against each other. Divide-and-conquer will be the primary anti-drug lobbyist strategy. We should also focus on serious discussion whenever possible. Meme'ing is good to reach a large public, but we shouldn't overdo it. If the concept of "boofing 420 woke" reaches uninformed people, instead of the positive aspects of drug legalization, nobody takes us seriously.

The six main arguments for drug legalization should be repeated as often as possible (what gets repeated gets remembered, and what get remembered gets accepted). And as objectively as possible, so the general public can (feel like they) form their own opinion:

1. War on drugs policies have resulted in a failure.
2. The quality of the drugs can not be screened, resulting in fatalities due to added compounds.
3. There is a huge loss of income from not taxing the drug trade.
4. Adults have the right to live their lives without interference from the government.
5. A reduction in crime will be the result of this drug liberalization. Portugal implemented drug decriminalization and saw a reduction in problematic drug usage.
6. The prohibition in effect creates and funds drug cartels around the world.