When Washington and Colorado residents voted to legalize marijuana in November—by 11-point margins in each state—18- to 21-year-old adults cast ballots for measures that left criminal sanctions affecting their age group untouched.

Leaders of the successful legalization campaigns told U.S. News that marijuana activists themselves devised the age restriction, and spokesmen for two of the largest national marijuana reform organizations said they won't push for lowering the age limit.

"It is still illegal for people under 21 to possess any amount of marijuana, and the penalties will be no different than they were before the initiative passed," explained Mason Tvert, a former co-director of the campaign in favor of Amendment 64, the Colorado pot-legalization initiative.

Tvert, who now acts as the spokesman for the Marijuana Policy Project, said it made sense to cap the pot-use age at 21 since Colorado doesn't allow anyone younger than that to consume alcohol, another "intoxicant."

Marijuana Policy Project, a large national group that invested heavily in the Colorado initiative, "will not be working to lower the age limit in Colorado or any other state that passes similar legislation including a 21 age limit," Tvert said.

Allen St. Pierre, the executive director of NORML—another influential pro-legalization group—explained to U.S. News that "NORML assists the victims of cannabis prohibition" and represents "the interests and concerns of the tens of millions of Americans who responsibly consume cannabis."

But, said St. Pierre, ongoing prohibition for 18- to 21-year-old adults isn't a concern for NORML.

"NORML's board of directors supports legal access to cannabis to be similar to that of alcohol," said St. Pierre in an E-mail. "If society deems 18 years old the age of 'consent,' fine. If society wants to stick with 21 years of age, fine with us too."

Alison Holcomb, director of the successful Washington state legalization campaign, told U.S. News that in her state, as in Colorado, there were no changes to punitive laws against marijuana possession by those younger than 21.

"For now we can begin with a standard that is familiar to voters," Holcomb said. "Perhaps in the future, penalties will be reserved for people who provide dangerous substances to more vulnerable users rather than the users themselves."

Marijuana activist and attorney Douglas Hiatt told U.S. News that he opposed Initiative 502—the successful Washington legalization measure—because "it didn't get rid of prohibition."

"Looks like kids are starting to get targeted for driving and they're still being cited for marijuana," observed Hiatt. "I fail to understand that you can buy a gun, join the military, get a gun and kill someone and you can't buy a marijuana cigarette. It's ridiculous."

The Colorado and Washington initiatives "duplicated the problem with alcohol" on college campuses, Hiatt said, and "in Washington they made it particularly bad by criminalizing DWI for any detectable amount of marijuana" in an 18- to 21-year-old driver's blood, a measurement that may or may not prove impairment.

Hiatt said MPP and NORML are “becoming the new establishment, they’re becoming conservative, and they think these pyrrhic victories are actually going to get us somewhere.”

Aaron Houston, executive director of Students for a Sensible Drug Policy—a group with chapters on college campuses nationwide—told U.S. News that the age restriction "comes up for us on a regular basis because the majority of our constituency is people between the ages of 18 and 21."

"The irony is that some of the most enthusiastic people about legalizing marijuana work to pass legalization measures that don't actually benefit them ... We've seen this in Colorado and Washington. It is an ongoing problem," said Houston.

"SSDP supported both the Washington and Colorado initiatives despite our misgivings. ... But we don't think it's the last step toward ending prohibition," Houston added.

"I don't think MPP or NORML would lead the charge [to lower the age limit] and I don't think they have the legislative muscle," Houston explained. "Am I optimistic that it will happen anytime soon? Absolutely not."

Brett Engle, president of the Auraria SSDP chapter in Denver, said that during the legalization campaign "many students asked if the age would be 18 and were disappointed when they found out it would be 21." Engle, who is 28, said "it seems silly that you can go to war to die for your country, but you can't have a beer. Considering that cannabis is even less dangerous than alcohol, I think there is even more reason for it to be available to all adults."

In addition to legal penalties, students at public universities will continue to suffer nosey RAs and by-the-book administrators if caught puffing a joint. At the University of Washington, Associate Vice President Norman G. Arkans told U.S. News, "nothing has changed."

The 43,000-student university, Arkans said, has opted to obey federal law rather than state law because it receives federal grants.

"Though consumption of marijuana may be legal in most of Washington State, it remains illegal to possess or consume it on University property," Arkans wrote in an E-mail. "So, no changes. It is illegal here and students could be subject to disciplinary action if they violate the federal statutes."

If busted with marijuana, students—no matter what age—will normally get a warning the first time, Arkans said, then "move through a series of increasingly serious discipline, from probation to possible expulsion."

Enforcing the federal prohibition on marijuana will prove complicated for the University of Washington, which has its own police force.

"I believe federal agents need to make arrests for federal offenses," noted Arkans, although campus police will be able to charge under-21 smokers. "Our police can refer, but have not done so as this is a new environment in the state."

At the University of Washington, there were 58 arrests for drug offenses in 2011 and 47 in 2012, according to numbers provided by the school. The majority of those arrests were for marijuana, but precise statistics were not available.

Despite the ambivalent and indifference of prominent marijuana reform advocates when it comes to ending pot prohibition for all adults, statistics show that young adults are far more likely than the general public to use marijuana.

According to the National Survey on Drug Use and Health, in 2010—before marijuana was legalized by any state—21.5 percent of American adults between the ages of 18 to 25 ignored legal prohibitions and used marijuana at least once in the past month. For adults 26 and older, the percentage was only 4.8 percent.

Even if the age limit is locked in for Colorado and Washington young adults, there's some hope for the prospects of 18- to 21-year-olds being able to legally enjoy marijuana in other states yet to act on legalization.

Mike Crawford, a former president of The Massachusetts Cannabis Reform Coalition who was on the group's board for ten years, told U.S. News that in 2016 he expects Massachusetts residents will vote on an initiative with an age limit of 18.

"Continuing a war on adult marijuana users between the ages of 18-21 is not acceptable," said Crawford, who believes the 18-year limit should be "the blueprint for these legalization initiatives in the future."