As recently as five years ago, the public opposed it 60/36. Now this.

Can the Gary Johnson poll surge be far behind?

A record-high 50% of Americans now say the use of marijuana should be made legal, up from 46% last year. Forty-six percent say marijuana use should remain illegal…

When Gallup first asked about legalizing marijuana, in 1969, 12% of Americans favored it, while 84% were opposed. Support remained in the mid-20s in Gallup measures from the late 1970s to the mid-1990s, but has crept up since, passing 30% in 2000 and 40% in 2009 before reaching the 50% level in this year’s Oct. 6-9 annual Crime survey…

Support for legalizing marijuana is directly and inversely proportional to age, ranging from 62% approval among those 18 to 29 down to 31% among those 65 and older. Liberals are twice as likely as conservatives to favor legalizing marijuana. And Democrats and independents are more likely to be in favor than are Republicans.

Follow the link up top and eyeball their graph, which is astounding. For more than 20 years, from the late 1970s to the late 1990s, public opposition was flat at approximately 25/73. In the early 2000s, the numbers softened to roughly 35/63 and held there until 2006, when the big shift began. The demographic breakdown:

Even at the bottom of that totem pole, the numbers in each group are up. When Pew polled this question last year, the split among self-identified Republicans was 24/71. Among conservative Republicans, it was 20/77. Among the 65+ crowd, it was 22/69. You’re seeing sudden double-digit or near-double-digit improvement in all three groups here and I’m not sure why. The explanation for the overall shift seems obvious — young adults, who are very much in favor of legalization, are replacing the elderly, who are very much opposed — but I can’t explain why today’s young adults would be more comfortable with legalization than, say, the young adults of 10 years ago, who surely smoked a bit o’ weed themselves during their college days. My own half-assed theory is that as marijuana has become more ubiquitous in music and movies and more prominent people have publicly acknowledged youthful drug use before going on to achieve colossal success (be it Steve Jobs or The One himself), the old “reefer madness” fears about pot as a gateway drug to crippling addiction have weakened. Beyond that, I suspect there’s some spillover effect here via rising support for, of all things, gay marriage. Revisit this post from March and have a look at the trend lines on that issue over the past 15 years compared to the trend lines on legalizing marijuana. Not an exact match, but broadly concurrent. It may be that as people warm up to the glorious libertarian principle of “I don’t like it, but if it doesn’t affect me, whatever” vis-a-vis gay marriage, it’s informing their thinking on unrelated issues like marijuana too. But I don’t know; my own views might be coloring that. What am I missing here?

Exit question: Time for Democrats to launch Operation Ganja in time for 2012?