There appears to be a shift in the United States in favor of relaxing marijuana laws, a topic that has dipped in and out of the national conversation for decades. Public perceptions about pot have come a long way, from the dire warnings of "Reefer Madness" to growing acceptance of medical marijuana. 
Members of a crowd numbering tens of thousands smoke and listen to live music at the Denver 420 Rally on April 20, 2013. Annual festivals celebrating marijuana are held around the world on April 20, a counterculture holiday. 
A man smokes a joint during the official opening night of Club 64, a marijuana social club in Denver, on New Year's Eve 2012. Voters in Colorado and Washington state passed referendums to legalize recreational marijuana on November 6, 2012. 
People light up near the Space Needle in Seattle after the law legalizing the recreational use of marijuana went into effect in Washington on December 6, 2012. 
Nutrient products are placed on shelves in the weGrow marijuana cultivation supply store during its grand opening on March 30, 2012, in Washington, D.C. The store is a one-stop-shop for supplies and training to grow plants indoors, except for the actual marijuana plants or seeds. Legislation was enacted in 2010 authorizing the establishment of regulated medical marijuana dispensaries in the nation's capital. 
Marijuana activist Steve DeAngelo wears a "Yes on Prop 19" button as he speaks during a news conference in Oakland, California, on October 12, 2010, to bring attention to the state measure to legalize marijuana for recreational purposes in California. Voters rejected the proposal. 
Sonja Gibbins walks through her growing warehouse in Fort Collins, Colorado, on April 19, 2010. Since the state approved medical marijuana in 2000, Colorado has seen a boom in marijuana dispensaries, trade shows and related businesses. So far 20 states and the District of Columbia have made smoking marijuana for medical purposes legal. 
A patient prepares to smoke at home in Portland, Maine, on October 22, 2009, a decade after the state approved a medical marijuana referendum. 
Coffeeshop Blue Sky worker Jon Sarro, left, shows a customer different strains of medical marijuana on July 22, 2009, in Oakland, California. Voters in the city approved a measure during a vote-by-mail special election for a new tax on sales of medicinal marijuana at cannabis dispensaries. 
Medicinal marijuana patient Angel Raich wipes her eyes during a press conference on March 14, 2007, in Oakland, California. The 9th circuit U.S. Court of Appeals in San Francisco ruled that 41-year-old Raich, who used medicinal marijuana to curb pain from a brain tumor as well as other ailments, did not have the legal right to claim medical necessity to avoid the possibility of prosecution under federal drug laws. 
Different varieties of medical marijuana are seen at the Alternative Herbal Health Services cannabis dispensary in San Francisco on April 24, 2006. The Food and Drug Administration issued a controversial statement a week earlier rejecting the use of medical marijuana, declaring that there is no scientific evidence supporting use of the drug for medical treatment. 
People in New York gather for a pro-cannabis rally on May 4, 2002. That same day, almost 200 similar events took place around the world to advocate for marijuana legalization. It was dubbed the "Million Marijuana March." 
Dennis Peron takes notes during a phone interview while Gary Johnson lights up at the Proposition 215 headquarters in San Francisco on October 11, 1996. The ballot measure was approved when voters went to the polls in November, allowing medical marijuana in California. 
A television ad aired in 1996 by Republican presidential candidate Bob Dole's campaign included footage from a 1992 MTV interview of a laughing President Clinton saying he would inhale marijuana if given the chance to relive his college days. 
President George H. Bush holds up a copy of the National Drug Control Strategy during a meeting in the Oval Office on September 5, 1989. In a televised address to the nation, Bush asked Americans to join the war on drugs. 
Robert Randall smokes marijuana that was prescribed to treat his glaucoma in 1988. He became the first legal medical marijuana patient in modern America after winning a landmark case in 1976. 
First lady Nancy Reagan participates in a drug education class at Island Park Elementary School on Mercer Island, Washington, on February 14, 1984. She later recalled, "A little girl raised her hand and said, 'Mrs. Reagan, what do you do if somebody offers you drugs?' And I said, 'Well, you just say no.' And there it was born." She became known for her involvement in the "Just Say No" campaign. 
President Jimmy Carter, with his special assistant for health issues, Dr. Peter Bourne, beside him, talks to reporters at the White House about his drug abuse control message to Congress on August 2, 1977. Among other things, he called for the elimination of all federal criminal penalties for the possession of up to one ounce of marijuana. 
Panel members of the National Commission on Marijuana and Drug Abuse attend a hearing In Denver on January 10, 1972. From left, Dr. J. Thomas Ungerleider, psychiatrist; Michael R. Sonnenreich, commission executive director; Raymond P. Shafer, commission chairman; Mitchell Ware, Chicago attorney; Charles O. Galvin, Dallas law school dean. The commission's findings favored ending marijuana prohibition and adopting other methods to discourage use, but the Nixon administration refused to implement its recommendations. 
Protesters wade in the Reflecting Pool at the National Mall in Washington during the "Honor America Day Smoke-In" thrown by marijuana activists in response to the official "Honor America Day" rally organized by President Nixon supporters at the Lincoln Memorial on July 4, 1970. 
Marijuana reform was the Life magazine cover story in October 1969. The banner read: "At least 12 million Americans have now tried it. Are penalties too severe? Should it be legalized?" 
Police dogs trained to smell out hidden marijuana examine U.S. soldiers' luggage at the airport during the Vietnam War in 1969. Drug use was widespread during the war. 
People share a joint during a 1969 concert in Portland, Oregon. In 1973, Oregon became the first state to decriminalize cannabis. 
Marijuana use became more widespread in the 1960s, reflecting the rising counterculture movement. 
Research scientist Dr. Reese T. Jones, right, adjusts the electrodes monitoring a volunteer's brain response to sound during an experiment in 1969 that used a controlled dosage of marijuana. The tests were conducted at the Langley Porter Institute at the University of California, San Francisco. 
U.S. Customs agents track the nationwide marijuana market during Operation Intercept, an anti-drug measure announced by President Nixon in 1969. The initiative intended to keep Mexican marijuana from entering the United States. 
Members of the Grateful Dead talk with reporters from their home in San Francisco on October 5, 1967. The band was protesting being arrested for marijuana possession. 
A woman buys ready-rolled marijuana cigarettes from a dealer at her door circa 1955. 
Even after Congress cracked down on marijuana in 1937, farmers were encouraged to grow the crop for rope, sails and parachutes during World War II. The "Hemp for Victory" film was released in 1942 by the U.S. Department of Agriculture. 
Marijuana cigarettes are hidden in a book circa 1940. Congress passed the Marijuana Tax Act in 1937, effectively criminalizing the drug. 
A poster advertises the 1936 scare film "Reefer Madness," which described marijuana as a "violent narcotic" that first renders "sudden, violent, uncontrollable laughter" on its users before "dangerous hallucinations" and then "acts of shocking violence ... ending often in incurable insanity." 
Harry Anslinger was named commissioner of the Federal Bureau of Narcotics when it was established in 1930. While arguing for marijuana prohibition, he played on Americans' fear of crime and foreigners. He spun tales of people driven to insanity or murder after ingesting the drug and spoke of the 2 to 3 tons of grass being produced in Mexico. "This, the Mexicans make into cigarettes, which they sell at two for 25 cents, mostly to white high school students," Anslinger told Congress. 
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- Dan Riffle: The war against marijuana has not worked, just like alcohol prohibition
- Riffle: Marijuana is far safer than alcohol; there are many alcohol-induced deaths
- He says we can take pot away from criminals and let licensed businesses handle it
- Riffle: Regulating marijuana would make America a safer and healthier nation
Editor's note: Dan Riffle is a former assistant prosecutor and the director of federal policies at the Marijuana Policy Project, the primary financial backer of the 2012 campaign to regulate marijuana in Colorado.
(CNN) -- Anti-marijuana crusaders like Kevin Sabet, while well-intentioned, are promoting policies that lead to more violence and disease in our society. In his recent CNN.com op-ed, Sabet argues we should keep marijuana illegal. But as long as marijuana remains illegal, profits from sales go to criminals and drug cartels, and adults will continue to be punished for using a substance less harmful than currently legal drugs.
Confused? Let's back up. For more than 80 years, our government has spent tens of billions of taxpayer dollars fighting a war against marijuana. We arrest three-quarters of a million adults every year, 87% for simple possession rather than production or sales of marijuana. Courtrooms turn into assembly lines churning out probationers -- mostly minorities -- with convictions that will make it virtually impossible to find employment.
The result? Marijuana is universally available, used by almost half of Americans at some point in their lives, and we've enriched murderous drug cartels fueling violence in Mexico that has claimed more than 60,000 lives.
Of course, we've been down this road before. During alcohol prohibition in the 1930s, federal agents raided speakeasies and busted barrels of illegally produced and imported booze. Meanwhile, bootleggers made money hand over fist, empowering criminals like Al Capone to turn Chicago into an urban war zone. And much like with marijuana today, even under alcohol prohibition most Americans who wanted a drink had no problem finding one.
Today, marijuana prohibition has proven itself just as disastrous a public policy failure as alcohol prohibition before it. Yet despite all the obvious similarities between the two, there's one key difference: Marijuana is dramatically safer than alcohol.
According to the Centers for Disease Control, excessive alcohol use is the third leading lifestyle-related cause of death. In a typical year, there are roughly 25,000 alcohol-induced deaths in the United States, most from long-term consequences like liver disease and some from acute alcohol poisoning brought on by binge drinking.
Marijuana, on the other hand, does not cause overdose deaths and comes with far fewer long-term health consequences. A 2009 Canadian study determined the annual health-related costs associated with alcohol are more than eight times greater per user than with marijuana. And, according to the Institute of Medicine, people who use marijuana are far less likely to become dependent than those who drink alcohol.
Seattle opens marijuana farmers market 
Washington details pot sale rules Even if you don't drink, alcohol can kill you. Federal agencies report that 40% of violent crimes in the U.S. are linked to alcohol use, whereas those same agencies report that marijuana users usually do not commit violent crimes. Alcohol plays a role in a third of all emergency room visits. As a prosecuting attorney, I often had police confess to me how much they loathed arresting drunks, given how often the situation escalated to violence. I never fielded similar complaints about marijuana consumers.
The irony is that these perverse policies are cheered on by organizations with names like "Save Our Society" that seem to believe chaos will somehow ensue if adults are no longer punished for using marijuana. The reality is that by punishing adults who would rather use marijuana, we're encouraging them to instead use alcohol -- a more dangerous and harmful, but legal, drug. Public policy should be geared toward reducing violence and disease, not maximizing them.
There is a better way. Polling shows a majority of Americans want marijuana taxed and regulated. A growing number of states are bucking our federal government's policy of absolute marijuana prohibition, and the Department of Justice recently signaled it will not challenge state laws that regulate the cultivation and sale of marijuana.
By doing so, we can take marijuana away from criminals and cartels and put it in the hands of licensed businesses. Obviously, those businesses should be subject to sensible rules ranging from where and when they can operate and who is able to invest in them, to restrictions on advertising.
Don't believe it could work? In 2009, Colorado's medical marijuana industry exploded, prompting the state to put in place the kinds of regulations I've just outlined. According to CDC data on youth drug use, from 2009 to 2011 -- a time when youth marijuana use increased nationally -- the percentage of Colorado teens using marijuana dropped more than any other state in the country and is now below the national average.
Marijuana is safer than alcohol; let's treat it that way. Adults who would prefer to use marijuana instead of alcohol should be free to do so. Just as significant, the law enforcement resources spent making those three-quarters of a million arrests could instead be devoted to preventing and solving real crimes.
In other words, regulating marijuana would make America a safer, healthier nation.
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The opinions expressed in this commentary are solely those of Dan Riffle.
