Editor's note: Republican Gary Johnson became the first candidate to formally announce his candidacy for the GOP presidential nomination today. This column about the former New Mexico governor originally ran on April 10, 2002.

The hypocrisy that surrounds the typical politician's approach to drugs was driven home to me one evening more than a decade ago during a trade trip to Asia. As we walked through an outdoor restaurant, the smell of smoldering hemp came wafting on the night wind.

"That smells like cannabis, " observed a certain insouciant prosecutor-turned-politician with a penchant for duck-hunting, fly-fishing, and a curious sport he called "deer drinking."

"Or at least," the same red-headed figure hastened to add, in a puckish bow to political caution, "what I'm told cannabis smells like."

Compare with that the cut-the-cant candor of Gary Johnson, the free-thinking Republican governor of New Mexico who has become a crusader for the legalization of marijuana and a shift from prosecution to harm-reduction strategies for hard drugs. Not for Johnson the cautious talk about youthful "experimenting" with pot; by those euphemistic standards, he would have been a full-bore research scientist during his college days.

"I smoked pot. That was something that we did," Johnson said during a Monday interview in Boston, part of an East Coast swing to address the Massachusetts Libertarian Party and speak at Dartmouth and Harvard.

How often? "I guess I smoked pot two and a half times a week," he says, a joking attempt to be exact. He also tried cocaine several times, but quickly decided it was too addictive to continue.

Johnson says he gave up marijuana after college, when he was training to become a ski racer. Comparing a downhill run performed on a Rocky Mountain high to one done under normal mental conditions, he was surprised that what had seemed like a lightning glide through the gates had actually taken precious seconds longer than his level-headed best. The 49-year-old triathlete and health nut, who now eschews alcohol, sugar, and caffeine, says that these days his only interest in pot is from a public policy standpoint.

So does Johnson's iconoclastic view on drugs trace from the libertarianism of philosopher John Stuart Mill, who thought that "over his own body and mind, the individual is sovereign" and that though government might entreat against, it had no right to forbid any behavior that doesn't harm others? In part, says Johnson. But a bigger reason was practical: When he became governor, in 1995, he quickly learned that battling drugs consumed huge chunks of law enforcement, prosecutorial, and penal resources.

"Half of everything we spend in those three areas is drug related," he said. In total, the United States devotes an estimated $40 billion to the war on drugs.

But what of the potential ill effects that would come of legalization of marijuana and effective decriminalization of other drugs? Johnson says the experience in other places, notably the Netherlands, makes him doubt general drug addiction would increase — and that if some people switched from drinking to dope, harmful side effects would likely decline because "so many abuse alcohol, and it is by far the worst of substances."

Still, in Amsterdam, where the use of hard drugs is effectively decriminalized and where one can buy marijuana and hashish in coffeehouses, regular warnings to be on guard against purse snatchers and pickpockets make the city feel as though a flock of fleet-fingered Fagans is afoot. "Statistically, that is not any different," Johnson insists of that sort of thievery. "What is different is violent crime: A quarter of the violent crime, a quarter of the homicide rate, a 10th the incarceration rate" of the United States.

It's been a slow swim, but Johnson is convinced the tide is beginning to turn.

"We have come to the point where it is safe to say treatment instead of incarceration," Johnson says. "I think very shortly we are going to repeal federal mandatory minimums. We are seeing the repeal of mandatory minimums in states."

After two terms as governor, Johnson leaves office early next year with no plans to seek another elected post. But you will still see him on the front lines of the battle against the war on drugs. "I passionately believe that there is not a bigger issue today that has a positive solution to it," Johnson says. "We could be treating this differently, and as a result we'd have a better world to live in."

Globe file photo: Gary Johnson in 1999, when he was the governor of New Mexico.