With just days to go before Election Day, voters in two states – Colorado and Washington – are poised to make history. 

In Colorado, voters will decide on  Amendment 64 , a Constitutional amendment that allows for those age 21 or older to legally possess up to one ounce of cannabis and cultivate up to six cannabis plants in the privacy of their home.  Longer-term, the measure seeks to establish regulations governing the commercial production and distribution of marijuana by licensed retailers. Voters in the state are backing the measure by a margin of 53 percent to 43 percent, according to the latest Public Policy Polling survey.

In Washington, voters will decide  on I-502 , a statewide ballot measure that enacts regulations regarding the state-licensed production and sale of marijuana for adults.  The measure also removes criminal penalties for adults who possess up to one ounce of cannabis for personal use.  According to a K ING 5/Survey USA poll published late this week, likely voters back the ballot initiative by a margin of 56 percent to 37 percent. 

(A similar Oregon initiative,  Measure 80 ,  trails in the polls with  only 42 percent support from likely voters.)

The passage of one or both of these statewide measures this Tuesday will be both historic and game-changing. Here’s why.

For the first time in well over seven decades, state law will declare that cannabis is no longer contraband

While a minority of marijuana law reform activists has griped that these measures do not go far enough, the reality is that their passage will provide cannabis consumers with unprecedented legal protections. Presently, no state legally defines cannabis as a legal commodity. Some state laws do provide for a legal exception that allows for certain qualified patients to possess specific amounts of cannabis as needed. But none of these states define cannabis itself as a legal product that may be lawfully possessed and consumed by adults.

The difference is hardly one of semantics. Consider this: Even in California, the state that is considered by many to possess the most liberal medical marijuana laws, police (and state law) define cannabis, even when present in only minor amounts, as contraband. This means that the presumption of law enforcement and prosecutors is that a person possesses or cultivates cannabis unlawfully. The burden, therefore, is on the would-be defendant to establish that they are legally exempt under the law as a qualified patient. In some cases, this might mean showing proper paperwork to a police officer. (The arresting officer may or may not choose to accept this paperwork as legitimate.) In other case, it may entail having to prove one’s case in a court of law. Either way, the mindset of the state is clear: cannabis is illegal – unless it can be established otherwise. 

Passage of either Amendment 64 or I-502 completely changes this dynamic. Rather than presuming cannabis to be illicit, and that those who possess it are engaged in illegal activity, passage of these measures will mandate law enforcement and prosecutors to presume that cannabis is in fact legal, and that those who possess it in personal use quantities are engaged in legal activity, unless the state can show that there are extenuating circumstances proving otherwise (e.g., a person possessed a greater quantity of cannabis than is allowed under state law). 

Further, since up to one ounce of cannabis will no longer be classified as an illicit commodity under state law, police will have no legal authority to seize it from lawful adults. This is just the opposite of the reality that exists now, even in the 14 states that have ‘decriminalized’ cannabis (replaced criminal sanctions for possession with civil fines). In all of these instances, police must seize the cannabis they encounter from the consumer – through the use of force, if necessary – even in cases where they are merely issuing a civil citation. That is because the law has only decriminalized the cannabis offense (e.g., simple possession); the cannabis itself remains criminalized. 

Finally, reclassifying cannabis under state law limits police from going on ‘fishing expeditions’ when they encounter it in ‘plain view’ – such as in someone’s home or in their car. Since marijuana is not contraband, police will no longer have sufficient cause to engage in a further search of the area because, legally, no criminal activity has taken place.

Colorado and Washington may be the first, but they won’t be the last

Prior to the passage of Proposition 215 by California voters in 1996, no state provided a legal exemption for qualified patients to possess or grow cannabis with a physician’s recommendation. But in the years since Californians made history, the landscape has changed remarkably. Today, seventeen states, as well as the District of Columbia, have similar marijuana medicalization on the books. Moreover, in recent years, several states have gone even further than Californians initially believed was possible. Many states, including Arizona, Colorado, New Mexico, and Maine, now license and authorize the production and sale of cannabis. (Two additional states,  Arkansas and  Massachusetts , have measures on the 2012 ballot to similarly allow for the state-authorized dispensing of medical cannabis.) And national polls show that  approximately 80 percent of Americans now agree that the physician-authorized use of cannabis should be lawful – a percentage that has grown dramatically since 56 percent of Californians first made this a mainstream political issue.

The reality: It took the decision of voters in just one state to change the political and legal landscape forever. This year’s votes in Colorado and Washington will do likewise.

Passage of Amendment 64 and I-502 mark the beginning of the end of cannabis prohibition

The criminalization of cannabis is a policy that has been in place federally since 1937 and on the state level, in many instances, long before that. Yet, it is a policy that fails to withstand serious scrutiny and possesses only limited public support. Today, a majority of Americans espouse ending America’s nearly century-long, failed experiment with cannabis prohibition and replacing it with a system of limited legalization and regulation. Recent national polls  by Gallup ,  Rasmussen , T he Huffington Post ,  and  Angus Reid show that more Americans now support legalizing the adult use of cannabis than support maintaining its prohibition. Now it is time for a state to make this sentiment a reality.

Similar to alcohol prohibition, cannabis prohibition is a federal policy that largely relies on state and local enforcement. How did federal alcohol prohibition come to an end? Simple. When a sufficient number of states – led by New York in 1923 (several other states, including Colorado, later followed) – enacted legislation repealing the state’s alcohol prohibition laws. With states no longer doing the federal government’s bidding to enforce an unpopular law, the Feds eventually had no choice but to abandon the policy altogether. 

Here’s to history repeating itself.