Five states, including California, will vote on legalization in November

Even support among Republicans has increased by double, to 42%

Support for the legalization of marijuana among the American public is now at 60 per cent says, polling company Gallup - that's the highest in its 47-year trend, and almost double what it was in 2005.

That enthusiasm is evenly spread across all ages, races, genders and political demographics, according to a poll of 1,017 adults who were asked 'Do you think the use of marijuana should be made legal or not?'

The lift in support comes as legalization measures appear on the ballots in five states this November, Gallup noted in Wednesday's poll.

Joint agreement: A Gallup poll says 60 per cent of Americans are now in favor of legalizing marijuana, up from 36 per cent in 2005 (pictured: Colorado 420 pro-weed rally, 2014)

Higher and higher: Approval for marijuana legalization has increased rapidly since the early 2000s. A long flat period in the 1980s coincides with the 'Just Say No' anti-drug campaign

The company first started asking the question in 1969, at which point just 12 per cent said that they were in favor of legalization.

That rose to 28 per cent in 1977, but dipped again and stayed around 25 per cent in the 1980s.

Perhaps not coincidentally, that was the period in which the US government ran its 'Just Say No' anti-drugs campaign.

But at the start of the 2000s it began to inch higher, hitting 36 per cent in 2005 and then ramping up to the present day rate of 60 per cent.

Politically, approval for legalizing pot spans the divide, with all groups showing an increase in approval: Democrats from 38 per cent in 2003 and 2005 to 67 per cent now, and independents up from 46 per cent to 70 per cent.

And while Republicans are on the whole less enthusiastic about getting high, support among their group has more than doubled, from 20-42 per cent.

Those figures combine 2003 and 2005 statistics because each survey only asked the question of a half-sample of respondents.

Red, blue and green: Increasing support for legalization spans parties, with even traditionally anti-pot Republicans experiencing a more than 100 per cent increase

Support has also increased across all age groups, from those aged 18 upwards.

And that approval might well continue to increase, Gallup suggested, if California decides to legalize marijuana in November.

That state is just one of five - the others being Arizona, Maine, Massachusetts and Nevada - looking at legalization this year.

But the 'Golden State' tends to set political trends for the US, Gallup says, and California giving the nod might well be the tipping point for the US.

Potted history: Increased approval likewise spans age ranges, with those who were children in 2003 and 2005 now firmly in favor of legalization

It might also end in a Supreme Court case similar to the one that saw gay marriage legalized across the US, the report said.



Buying pot for medicinal and recreational purposes is already legal in Washington and Colorado, and more than half the US has legalized marijuana use in some way.

Gallup notes that the 60 per cent approval noted in this poll is statistically similar to the 58 per cent recorded in 2013 and 2015, so it's not known whether support is actually larger or has just stabilized.