Democratic state Senate candidate Katherine Clark pounced on her Republican opponent Craig Spadafora saying at Wednesday night's debate he would support the legalization of marijuana and not tax it, sending out a press release on Thursday with comments from the Melrose and Wakefield police chiefs condemning Spadafora's stance.

At Wednesday's debate, Melrose Free Press editor Carol Brooks Ball said that Green-Rainbow gubernatorial candidate and doctor Jill Stein attended Saturday's annual MassCann Freedom Rally on Boston Common and called for legalizing marijuana to disrupt the black market for the drug and raise revenues for the state.

Brooks Ball asked Clark and Spadafora—who are running for the state Senate seat representing Melrose Wards 1-5 that is being vacated by lieutenant governor candidate Sen. Richard Tisei, R-Wakefield—how they would vote on legalizing marijuana.

Spadafora responded that he would vote to legalize marijuana, "not for the tax. The problem is we're overcrowding our prisons with non-violent offenders."

Clark said she would not vote for legalizing marijuana—although she said "I think we can carve out an exception for medicinal use"—and preferred having the state look at its mandatory minimum sentences for marijuana and put money towards diversion and other programs, "so we're not paying $56,000 a year to lock up a person whose problem is addiction."

In her follow-up question, Clark asked Spadafora if he was in favor of legalizing marijuana why he would not want to tax it. After first saying that he originally said that he thought the state would tax it and being pushed by Clark, Spadafora said flatly, "I would not support a tax on marijuana."

Clark calls legalization and non-taxation "dangerous policy;" Spadafora cites cost savings, public support

In her press release on Thursday, Clark cited her former work as a prosecutor, where she said that she saw the drug and alcohol problems in local communities and the "crisis of funding" to support law enforcement and treatment facilities. She attacked both Spadafora's support of legalization and his stance against taxing it to raise funds for public safety.

"Craig Spadafora's support for legalizing marijuana and opposition to funding to support law enforcement and public safety is dangerous policy and sends the wrong message to the children and teens in our communities," she said.

In response, Spadafora issued a statement on Friday saying that an overwhelming majority of voters—65 percent—approved a ballot initiative in 2008 to decriminalize possession of small amounts of marijuana, making possession of less than an ounce of pot punishable by a civil fine of $100.

Spadafora said that decriminalization "proposed over $30 million dollars in annual savings for tax payers by freeing up police to focus on more serious crimes."

Harvard University economics lecturer Jeffrey Miron estimated in a 2008 report (PDF) that Massachusetts would save $29.5 million in criminal justice costs by decriminalizing marijuana. In Rhode Island, where a state Senate commission recommended a decriminalization law similar to Massachusetts, estimates of how much the state could save on prison costs ranged from $232,000 to $2 million, according to the Providence Journal.

Spadafora also said that recent polls suggest 70 percent of Massachusetts residents either favor decriminalization or legalization of marijuana.

"My views regarding marijuana policy align with the majority of the taxpayers," he said, adding that marijuana policy is not one of his campaign platforms and he does not intend to be an outspoken advocate for legalization if elected. "That being said, I don't think that during these times of economic uncertainty, we should be focusing on issues such as legalizing marijuana. As much as my opponent would like to deflect the focus of this debate away from her irresponsible and inconsistent voting record, my focus remains to be job creation and tax reduction—two areas where she has come up short in delivering on as a legislator."

Is marijuana a gateway drug?

Clark's press release also quoted Wakefield Police Chief Rick Smith as saying "this is a terrible idea and I'm dead set against it" and Melrose Police Chief Mike Lyle as "adamantly" opposing the legalization of marijuana.

"I look at marijuana as a gateway drug," Lyle said. "We don't have enough treatment centers for kids that are hooked on drugs today."

A recent study by researchers at the University of New Hampshire said that marijuana's role as a gateway drug is overblown and more dependent on social factors than the actual drug, while the Institute of Medicine (IOM) of the National Academies said in a 1999 study that "there is no evidence that marijuana serves as a stepping stone on the basis of its particular physiological effect."

"Whereas the stepping stone hypothesis presumes a predominantly physiological component of drug progression, the gateway theory is a social theory," the IOM study said. "The latter does not suggest that the pharmacological qualities of marijuana make it a risk factor for progression to other drug use. Instead, the legal status of marijuana makes it a gateway drug ... in the sense that marijuana use typically precedes rather than follows initiation into the use of other illicit drugs, it is indeed a gateway drug.

"However, it does not appear to be a gateway drug to the extent that it is the cause or even that it is the most significant predictor of serious drug abuse; that is, care must be taken not to attribute cause to association," the study said.

Increasing marijuana potency, rise in use worries public health officials

Public health officials are still on watch against marijuana. Last week the federal Substance Abuse and Mental Health Services released its annual report on illegal drug use, which reported that the rate of illegal drug use rose in 2009 to the highest level in nearly a decade. Government officials blamed increasing use of marijuana—up 8 percent—for the overall rising rate.

Also, government-funded studies have concluded that marijuana's potency has risen over the past three decades, which health officials say has led to increased addiction rates and more adults being admitted to treatment centers for marijuana use.

Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, a government agency, told the New York Times last year, "It's like drinking beer versus drinking whiskey. If you only have access to whiskey, your risk is going to be higher for addiction. Now that people have access to very high potency marijuana, the game is different."

According to the FBI's annual Uniform Crime Report, 858,408 people were prosecuted for marijuana violations in 2009, approximately 52 percent of all drug arrests in the U.S. Of those prosecuted, 88 percent were charged with possession and the remaining 12 percent were charged with sale or manufacture of marijuana.

In terms of taxation and for comparison's sake, in fiscal 2010, Massachusetts brought in almost $580 million from cigarette taxes. According to statistics from the state Department of Public Health, in 2008 the rate of adult smokers in Massachusetts was 16.1 percent; that rate has annually declined since 1986, when the rate of adult smokers in the state was 27.8 percent.