The poll, which has tracked support for legal marijuana since 1973, found that approval reached an all-time high across all age groups, US regions, and political affiliations in 2018.
The numbers reflect how attitudes towards the drug are shifting across the nation. While the majority of Americans want the legalization of cannabis now, only 16% did in 1987 and 1990, the years with the joint-lowest support.
Consumption has also become more accepted across the US. Ten states, including California, Colorado, Michigan, have legalized the use of recreational marijuana, and 33 states allow its medical use.
See more: This map shows every US state where pot is legal
Though support grew across all age brackets, it remains the highest among 18 - 34-year-olds, the GSS found. More than 70% of young Americans say they want pot to be legal, while only 42% of interviewees over 65 say the same.
Survey takers in the Midwest are most in favor, at 68%. While support was lowest in the South, more than half of respondents there still said marijuana should be legalized.
On the political spectrum, Democrats (69%) and independents (66%) were largely in favor of legalizing weed. Only 42% of Republicans agreed, but support among them has been growing steadily over the years. In 2012, only a third of Republican voters wanted cannabis to be legal.
Now growing public support has all 2020 presidential candidates backing different efforts to legalize marijuana whether they are Democrats or Republicans.
Sen. Corey Booker has made legalization a centerpiece of his campaign, Elizabeth Warren is pushing to protect the pot industry, and President Donald Trump has said states should have the right to legalize pot if they want.
Read more: Here's where all the 2020 presidential candidates stand on marijuana legalization
John Lapp, a Democratic national campaign strategist, told The Boston Globe that the political evolution has been remarkable.
"Marijuana legalization, if you look back, was really something for fringe candidates. Its just not very controversial at all now," he said.
SEE ALSO: 10 things that can happen after a state legalizes marijuana