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. Predictably enough, the young are very strongly in favour, but babyboomers are almost as strongly so; and even those over 65 are narrowly in favour as well. Breaking the poll down by party, one finds that Republicans as well as Democrats are in favour, though the former much more narrowly so.

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. A ballot initiative that would have legalised the sale of marijuana was only narrowly defeated in California last November, possibly losing some potential supporters because the drug is already very widely available and possession is no longer treated as a crime. The full poll, which also shows Barack Obama's ratings continuing to improve, is available online.