Almost two-thirds of Americans think marijuana should be legal, according to a Gallup poll released Monday. 

That represents the highest number in the nearly 50 years since the polling organization began asking about the issue, according to a press release. 

The findings come as four states prepare to vote on November ballot initiatives that would increase momentum behind legalization of the drug for recreational and medical use.  

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Voters in Michigan and North Dakota will decide whether to legalize recreational marijuana for adult use. Missouri has three initiatives on the ballot that would legalize marijuana for medical use. And Utah has a medical marijuana measure on its ballot. 

Democrats and independents remained more likely than Republicans to say marijuana should be legalized, the poll found. But for the first time, a majority of Republicans — 51 percent — also expressed support for legalization. That’s up 9 percentage points from last year. 

The Gallup figures were based on poll conducted Oct. 5-11. The margin of error was plus or minus 4 percentage points.