How did the world change on 8 November 2016? No, it was not the election of Donald Trump. It was the passage of California’s proposition 64, removing legal controls on the production and sale of marijuana.

A quarter of Americans will now be able to buy cannabis legally, from California to Massachusetts, from Florida to Colorado. It is inconceivable that a Trump presidency will intervene in states’ rights and overrule them. The dam has broken. As with alcohol prohibition in the 1930s, the irresistible force of public demand has overwhelmed the immovable object of prejudice.

As these laws crumble across America, moves to tax marijuana will increase

The issue is not the harm marijuana does to its user – like nicotine and alcohol it can be severe – it is the harm that futile attempts to ban it do to society. Millions of people use cannabis in various forms across the world. In America it is assessed as an illicit $50bn industry. Its prohibition has failed as completely as did alcohol prohibition. It has merely bred secondary industries of criminality, smuggling, law (non-)enforcement, imprisonment and self-righteous lobbying, all with a vested interest in continued suppression.

As these laws crumble across America, moves to tax marijuana will increase. If Colorado is any guide, taxation could transform state budgets, aiding welfare and healthcare. It should also aid America’s appalling prison record, especially for ethnic minorities. Then reformers can tackle the equally futile suppression of other narcotics, such as cocaine.

America’s drug consumption has been the biggest destabiliser of its own urban economy and of the economies of its neighbours to the south. It has enslaved parts of Latin America for half a century. Legalisation should yield massive benefits. Proposition 64 will be far more transformative to American society than any small earthquake in Washington.

For Britain the lesson is grim. Still under the shadow of the archaic and unworkable 1971 Misuse of Drugs Act, its prisons are bursting at the seams. In our prisons, drugs find their way in all too easily, and drug use is higher there than in any other institutions in the land – a laugh in the face of a prohibitionist Home Office. While European nations from the Baltic to the Atlantic move slowly towards liberalisation, reactionary Britain holds out for idiocy.

California led the world in two modern-day revolutions, in film-making and computing. It has now championed a third. Drugs are not good for people. But drugs there are, and always will be. Trying to suppress them through a false faith in the great god government merely delivers greater evils. It will be years before antediluvian Britain recognises this. But for the moment, thank you California.