Biden: There's no proof marijuana isn't a gateway drug

2020 candidate Joe Biden said Saturday there would need to be more research into marijuana's effects before he'd ever federally legalize the drug as president, in order to rule out whether it's a "gateway drug."

The big picture: Several 2020 candidates have proposed to end the war on drugs and legalize marijuana. When Biden was vice president, he supported decriminalization rather than legalization.

There’s not nearly been enough evidence that has been acquired as to whether or not it is a gateway drug."

Details: Biden said during a town hall in Las Vegas that states "should be able to make a judgment" on whether to legalize marijuana.

• He said he supports medical marijuana and that possession of the drug "should not be a crime."

What they're saying: The National Institute on Drug Abuse says in a blog post that "some research suggests that marijuana use is likely to precede use of other licit and illicit substances." However, most marijuana users "do not go on to use other, 'harder' substances," it states.

Watch Biden speak at the town hall below.

• His marijuana remarks occur at about 36:30.

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