This week’s Economist-YouGov poll contains some exciting news for devotees of the weed. A huge majority of Americans, more than two to one once don’t knows have been excluded, support the legalisation and taxation of marijuana. Even without excluding the don’t knows, a clear majority favours treating the drug equivalently to tobacco and alcohol. The data (see chart) reveal some interesting patterns. In every age group, more people favour than oppose legalisation. If our poll is right, then it can only be a matter of time before laws start to change, at least in the more liberal states.