Five states will vote on whether to fully legalize marijuana in November. And supporters of those initiatives just got some pretty good news: Support for marijuana legalization in the US has reached historic highs.

A Pew Research Center survey of 1,201 US adults, conducted in late August and early September, found that 57 percent support legalization, while just 37 percent oppose it. That’s up from 53 percent support in 2014 and a near reversal from just a decade ago, when 32 percent backed legalization and 60 percent opposed it.

The trend is driven largely by millennials (ages 18 to 35), although support has gone up among other age groups, according to Pew. A majority of Republicans (55 percent) still oppose legalization, while most Democrats (66 percent) and independents (63 percent) support it.

The age demographics are a big reason advocates are so confident that legalization is inevitable: As younger people grow up and increasingly dominate politics, it’s going to be much more difficult for lawmakers to oppose relaxing marijuana laws.

Voters in Arizona, California, Maine, Massachusetts, and Nevada will vote on whether to legalize marijuana for recreational purposes this November, while voters in Arkansas, Florida, Montana, and North Dakota will vote on medical marijuana legalization. To read more about all the initiatives and state-level polling, check out Vox’s explainer.

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