Supporters of legalizing the recreational use of marijuana — a question California voters will decide on Tuesday — point to the benefits of taxing marijuana sales as an argument for legalizing the drug. Certainly the potential is there, but don't hold your breath waiting for revenue to flow into government coffers.

Supporters of legalizing the recreational use of marijuana — a question California voters will decide on Tuesday — point to the benefits of taxing marijuana sales as an argument for legalizing the drug. Certainly the potential is there, but don't hold your breath waiting for revenue to flow into government coffers.

Legalizing recreational pot use is easy. Taxing it effectively would be difficult at best and perhaps impossible, even with a new regulatory bureaucracy.

In fact, the medical marijuana system is far better suited to generate tax revenue than full legalization would be.

As The Associated Press reported in Sunday's Mail Tribune, the city of Oakland already taxes marijuana distributed by dispensaries for medical purposes, and several other cities are preparing to follow suit. Oregon's Ballot Measure 74 also would generate some revenue for the government by charging the new dispensaries a licensing fee.

That's relatively simple, because purchasers are limited to medical marijuana card holders, and the dispensaries are licensed by the state.

California's Proposition 19 would legalize the sale of small amounts of marijuana to any adult. It would tax those transactions by requiring sellers to be licensed under local ordinances yet to be drafted.

Sales by unlicensed individuals would remain illegal. But growing marijuana for personal use would be allowed.

Recreational marijuana users have been buying the drug illegally for generations. Expecting them to stop doing so, especially when they would have to pay a tax to buy it legally, is unrealistic.

Permitting everyone to grow marijuana also would undercut the taxing scheme.

Taxes on alcohol are efficient because, while it is legal to make beer and wine at home, it's hard to do, and even harder to do well. As a result, few alcohol consumers bother.

Marijuana, on the other hand, is comparatively easy to grow. There's a reason why one of the slang terms for it is "weed."

It's reasonable to assume that many users would simply plant a crop in the backyard, or under lights in the garage, thereby avoiding all taxes.

There are arguments to be made for legalizing marijuana, as well as arguments against it. That's a debate for another day, at least in Oregon.

But to those who suggest legalization would instantly pour money into government coffers, we would ask, what are they smoking?