I was on the floor of the state Assembly Thursday for the big vote on expanding the state’s medicinal marijuana program.

The bill passed overwhelmingly with bipartisan support, but not before the Republicans raised an interesting question.

That came when Assemblyman John DiMaio of Warren County questioned why the bill continues to impose the state sales tax of 6.625 percent on medicinal marijuana.

“I don’t believe we should be taxing medicine,” DiMaio said.

He went on to say that there are many people who don’t want to use prescription drugs for pain relief and would prefer cannabinoids.

“It’s immoral to tax their medicine,” he said.

Immoral or not, that tax stayed in the bill, which greatly widens the access to medical marijuana as compared to current law.

DiMaio’s effort to amend it failed in a vote that went along party lines.

The final bill passed by a 65-5 margin. A similar margin is expected when it comes before the state Senate, presumably this week, at which point it would go to Gov. Phil Murphy for his signature.

But the question lingered in my mind: Why would the state tax medicinal pot but not other legal pain-killers?

I soon got an answer, though I found it hard to believe.

The answer came from Assemblywoman Nancy Munoz, a Union County Republican who is a nurse in real life.

Munoz told me the Murphy administration does indeed intend to tax prescription pain-killers.

I told her she must be mistaken. That would be crazy.

She agreed it was crazy. But she wasn’t mistaken. In short order her aide, Mark Doherty, dug out a copy of the budget and showed me the line item listed under “Major Taxes” as “Opioid Assessment.”

That tax on prescription opioids is expected to bring in $21.5 million in the coming fiscal year, which begins July 1.

“You don’t tax legal drugs,” she said. “I have patients who are in unbelievable chronic pain, people who actually function very well with their opioids. I have elderly women with crushed vertebrae. You can’t fix this, but they can function with the drugs.”

When she discussed this with the administration, Murphy said, she was told that the money raised by the tax would go to fund programs to reduce opioid abuse. There are two problems with this, she said.

One: “They’re going to tax a legitimate drug, a legal drug, to fix the problem with bad behavior of others?”

Two: The revenue does not go to fund treatment. It’s listed in the budget as going into the General Fund. Once money goes into the General Fund, there is no limitation on how it’s spent.

Munoz said she was told by the Murphy administration that the tax will be imposed solely on the manufacturers and distributors of opioids, not the consumers.

“Have you ever seen a tax that wasn’t passed on to consumers?” she asked.

You’re not likely to in this case. New York Gov. Andrew Cuomo tried that trick last year with a similar tax, but a court ruled that violates the Commerce Clause

of the U.S. Constitution.

The bill enabling the tax has not yet been passed, so we still don’t know what the lawmakers have in mind for New Jerseyans who need prescription opioids. The Murphy administration didn’t respond to my call for comment, but state Senate Budget Committee chairman Paul Sarlo did.

The Bergen County Democrat said that at the moment most people have such a negative view of the drug manufacturers that this tax should be a popular one.

“Of all the revenue-raisers that might be easier to do because there’s so much anger toward the manufacturers,” he said. “That’s an argument. I’m not defending it.”

When I asked him whether the cost would be passed on to consumers, he replied, “I’m sure the manufacturers will find a way to do that.”

I’m sure they will, too. It would be great if the state could tax the people pushing illegal opioids into bankruptcy. But that goal won’t be achieved by taxing legal pain-killers.

If these guys really need the money so bad, then they might as well find a way to legalize adult-use marijuana in this budget. There aren’t enough votes for that at the moment. But it would bring in three times as much money, all of it from willing consumers.

Actually, many of those willing consumers will be getting their medicinal-marijuana cards right after the governor signs that medicinal-marijuana bill into law. I suspect the vast majority of them won’t mind paying a sales tax equal to the tax they pay when they buy beer or wine.

But when it comes to prescription medications, the government has already made a big enough mess.

No need to make it any worse.

BELOW - STOP FUNDING THE ADDICTION-INDUSTRIAL COMPLEX: Perhaps the most trenchant critic of the current system of treating drug addiction is psychologist Stanton Peele, who was until recently living in Morristown.

Many conservative commentators - including the late William F. Buckley - have argued that the War on Drugs has actually led people to move from relatively harmless drugs like marijuana to hard-core drugs like heroin and now Fentanyl.

It’s easy to demonize the big pharmaceutical companies for selling legal drugs that sometimes end up on the black market. But that doesn’t attack the real problem, which comes from synthetic drugs that can be made relatively easily in undergrounds labs.

In this case, the administration is just looking to make a quick buck by demonizing the drug sellers. But this is an exceptionally dumb move for a state that is home to quite a few such companies.

Do we want some of our best employers headed for other states with lower taxes and less regulation?

Apparently so.