TRENTON -- Gov. Chris Christie said he knows he is likely the only obstacle to legalizing recreation marijuana in New Jersey and he's "damn" proud of it.

"To me, legalization of marijuana for tax purposes -- and that is the only way people justify it -- is blood money," Christie told a caller on his monthly "Ask the Governor" radio program Monday night on 101.5-FM.

"I have watched too many kids start their addiction to alcohol and marijuana and then move on to much more serious drugs," the Republican governor said. "Every study shows marijuana is a gateway drug. And every study shows it causes damage."

Christie ripped into the caller who said a handful of legislators who had recently visited Colorado blamed the governor for blocking a legalization bill in New Jersey. The caller suggested the money could be used to roll back the gas tax increase that took effect on Nov. 1.

"Are you high?" Christie asked the caller sarcastically, noting the gas tax will generate $1.2 billion a year.

Colorado took in $135 million in tax revenue last year.

But even if legal pot could match the gas tax revenue, Christie said he wouldn't change his mind.

"There is nothing we spend in government that is important enough to allow me to willfully poison our children. That's blood money," Christie said. "You're damn right I am the only impediment. I'm going remain to be the only impediment until January 18, 2018," his last day in office.

According to the website for the National Institute on Drug Abuse, a federal agency, "further research is needed to explore this question" of whether marijuana is a gateway drug.

Studies in animals have shown marijuana can "prime" the brain for enhanced responses to other drugs, according to the website. "An alternative to the gateway-drug hypothesis is that people who are more vulnerable to drug-taking are simply more likely to start with readily available substances like marijuana, tobacco, or alcohol, and their subsequent social interactions with other substance users increases their chances of trying other drugs."

Christie also took a swipe at Phil Murphy, the leading Democratic contender for governor in 2017, without mentioning him by name. Murphy has said he supports legalizing and taxing marijuana.

"You want to bring some other joker in here who is going to make the argument to you this is all about the tax money? Then watch what happens to productivity, what what happens in our schools," Christie said. "Quite frankly, I think it is reprehensible to say you want to let this poison be legalized in our state for money."

New Jersey operates a medical marijuana program for more than 9,500 people, and they pay 7 percent sales tax for their medicine, Chris Goldstein of the Coalition for Medical Marijuana- New Jersey noted on Tuesday.

"Gov. Christie personally insisted on the only marijuana tax in New Jersey, one paid by seriously ill medical cannabis patients. He certainly has no problem with collecting pot taxes," Goldstein said.

The Christie administration has declined to reveal the amount of tax revenue generated by the medical marijuana program, in order to protect the private business interests of the few dispensaries that operate in the state. There are five dispensaries.

Susan K. Livio may be reached at slivio@njadvancemedia.com. Follow her on Twitter @SusanKLivio. Find NJ.com Politics on Facebook.