As the question of whether marijuana should be legal comes up for a vote in several U.S. states in this upcoming election, support for legal pot is at its highest in nearly 50 years, according to a new poll.

The poll, from Gallup, found that 60 percent of Americans now say that using marijuana should be legal. That's the highest level of support in the 47 years that Gallup has asked the question.

In 1969, when Gallup first surveyed Americans about whether they thought pot should be legal, just 12 percent said yes. During the 1980s and 1990s, support for legalizing pot hovered around 25 percent. But since the year 2000, support for legalizing marijuana has been on the rise. [Healing Herb? Marijuana Could Treat These 5 Conditions]

The year 2013 marked the first time that more than 50 percent of Americans polled said that they supported legalizing marijuana — the same year that Colorado and Washington voted to legalize marijuana for recreational use, Gallup said. Last year, 58 percent of Americans said they thought using pot should be legal.

In the upcoming election on Nov. 8, five states — California, Arizona, Massachusetts, Maine and Nevada — will vote on whether to legalize marijuana for recreational use. Recreational marijuana is currently legal in four states and the District of Columbia.

Support for legalizing marijuana has increased more among younger people, with those in older age groups, Gallup said. From 2005 to 2016, support for legalizing marijuana increased 33 percentage points among those adults ages 18 to 34, compared to 26 percentage points among those ages 35 to 54, and 16 percentage points among those ages 55 and older. Currently, 77 percent of adults ages 18 to 34 support legalizing marijuana, compared with 45 percent of adults ages 55 and older.

Democrats are also more likely to support legalizing pot than Republicans. In 2016, 67 percent of Democrats said marijuana should be legal, compared to 42 percent of Republicans.

If California votes to legalize recreational marijuana in the upcoming election, many other states could follow, because California often sets trends for the rest of the country, Gallup said.

"As more states legalize marijuana, the question of whether the drug should be legal may become when it will be legal," Gallup said in a statement.

The 2016 Gallup poll results are based on a survey of more than 1,000 Americans ages 18 and older, who were interviewed from Oct. 5 to Oct. 9. Participants were asked, "Do you think the use of marijuana should be made legal, or not?" The poll has a margin of error of plus or minus 4 percentage points.

Original article on Live Science.