On Wednesday, Bernie Sanders took a truly historic position: He became the first major presidential candidate to support removing marijuana from the US drug schedules and ending prohibition at the federal level.

But more than making history, Sanders took the only position on marijuana that's actually consistent with states' rights. In fact, it's the only position consistent with what much of the presidential field, including Democrats, has said but not followed up on: that marijuana policy should be left to the states.

Sanders's plan would not legalize marijuana nationwide. It would simply exempt pot from the federal scheduling system, much in the same way alcohol and tobacco are exempted. This means states could still choose to prohibit marijuana or legalize it — but they would no longer face the threat of federal interference if they did legalize.

Most of the presidential candidates say this is what they want: Although candidates like Hillary Clinton, Martin O'Malley, and Jeb Bush personally oppose or are unsure about marijuana legalization, they have said they wouldn't interfere with states' decision to legalize if elected president. This stance seems to embrace a continuation of the Obama administration's approach, in which states that legalize are largely left alone as long as pot doesn't fall into kids' or criminal organizations' hands.

But even the Obama administration's approach leaves major federal restrictions on pot. Marijuana's schedule 1 status makes it difficult for researchers to study the drug. It makes it harder for pot businesses to use banking services, forcing many to lie on applications to banks or run as cash-only operations. It means pot shops can't file for tax deductions available to other businesses, sometimes pushing their effective tax rates to as high as 90 percent. And since marijuana is still considered a dangerous and highly prohibited schedule 1 drug, the Drug Enforcement Administration can still technically raid marijuana shops at its whim (and it does).

Sanders's plan would address all of these issues: By taking marijuana out of the federal drug schedules, the proposal would let state-legal pot shops and growers truly operate without the constant fear of the federal government cracking down on them.

Other candidates support easing restrictions. Martin O'Malley and Rand Paul said they would like to reclassify marijuana from schedule 1 to schedule 2. But this would still maintain heavy restrictions on marijuana, particularly on business tax deductions. (Remember: Cocaine and meth are still schedule 2.)

Sanders's plan, then, would do the most to let states legalize marijuana. He's the only candidate really putting his policies where his words are when it comes to legalization.