For a third straight year, a majority of Americans has expressed support for making marijuana use legal, with younger people, Democrats and political independents most likely to favor legalization, a Gallup poll released on Wednesday found.
In the nationwide survey of 1,015 adults, conducted by telephone from Oct. 7 to Oct. 11, 58 percent of respondents backed legal marijuana use.
The findings maintained the upward trend of support for legalization documented over the past half century. Only 12 percent favored legalization in 1969, Gallup said.
In 2013, a majority, also 58 percent, for the first time backed marijuana legalization, Gallup said. Support for marijuana legalization stood at 51 percent in Gallup's poll last year.
Younger generations were more supportive than older generations, who are more supportive than they have been in the past, Gallup said of this year's poll. Now only those 65 and older as an age group oppose legalizing marijuana, it said.
Gallup said Democrats and independents were the most likely of the major political groups to favor legalizing marijuana, while Republicans were least likely.
Voters have approved general marijuana use and possession by adults under state-regulated frameworks in four states, Oregon, Alaska, Washington state and Colorado, as well as the District of Columbia.
While marijuana use remains illegal for any reason under federal law, 23 states allow marijuana for medical purposes. Legalization measures will be on the ballot in Ohio in November and in other states in 2016.
By the late 1970s, support for legal marijuana rose to about 25 percent and stayed there through the mid-1990s, Gallup said. By 2000, more than 30 percent favored legalization and by 2009, more than 40 percent.
The margin of error of the new Gallup poll was plus or minus 4 percentage points.
(Reporting by Suzannah Gonzales; Editing by Will Dunham)