But Gary Johnson, New Mexico's GOP governor, argues today's marijuana laws are no more effective than prohibition. He supports legalizing marijuana - as well as modifying other drug laws to emphasize treatment and prevention, instead of punishment, for nonviolent offenders.
Since Johnson's message doesn't flow gently into the Republican mainstream, he made his case to a friendly crowd at the Shadow Convention on Tuesday.
"This is the biggest problem in the country that is absolutely going unaddressed," said the governor after addressing this week's counter-event to his own party's gathering.
"Let's get back to victim crimes and non-victim crimes," Johnson told reporters and a few onlookers. "And I suggest that we should continue to be tough on individuals that do drugs and do crime just like individuals that would drink and do crime."
Approximately 458,000 men and women in the United States are now serving drug sentences - more than ten times the number 20 years ago.
Johnson could have been one of them. He told CBS News' 60 Minutes this year that in his youth he used marijuana and tried cocaine twice.
But those days are long ago: the governor labels himself a "health fanatic" who touches no alcohol, tobacco or coffee - and even eyes sugar with suspicion.
As an exotic political species - a Republican challenging America's "war on drugs" - the governor acknowledged he's a lone voice, but added that role comes with the territory.
"I get a sense that there is an education going on, that we do need to stop 'getting tougher,'" he said. "I don't want to single out Republicans as being to blame for the current state of the drug war. I think that Republicans and Democrats both can share responsibility for it."
A woman who described herself as a Republican caught Johnson's Shadow Convention remarks and then scolded the governor in front of reporters and onlookers.
"It's absolutely unbelievable that a person of your stature would go in there and say the things that you did," she told him.
Johnson tried reasoning with her, but she moved on.
"There's a good chance that that person probably drinks alcohol," said the governor of his confronter. "And at one point in this country's history, alcohol was also a crime. Personally, I don't condone alcohol use, but not for a minute do I think that alcohol use should be criminal. The effect of what it is that's happening in this country is we are arresting and incarcerating this country - and that's the fact."
On that score, the statistics don't lie. In 1997, the last year for which numbers are available, nearly 80 percent of U.S. drug arrests were for possession. Of that total, 44 percent were for marijuana.
Race is prt of the picture, too. While African Americans comprise 13 percent of America's regular drug users, 62.7 percent of those sent to prison for drug-related offenses are black.
In this year's race for the White House, Johnson called his cause an "absolute political taboo."
"Are either of the presidential candidates gonna address this?," he asked in a rhetorical fashion about George W. Bush and Al Gore. "No, they're not. It would be the end of their campaigns. They can't address it. I understand that. I mean, that's just the way that it is."
Johnson, who backs fellow GOP governor Bush for president, said he's made his legalization views clear to the Texan's campaign. He even went as far to say he believed such views would get a better hearing from Bush than Gore. But Johnson didn't explain why, beyond his presumable party loyalty. Nor would he divulge details of any drug policy talks he's had with the Bush camp.
"Anything that I infer might be reflected on the (Bush) campaign and I don't want that to happen," he said.
The governor agreed that a Nixon-Goes-To-China move may be the only way to create what he considers a necessary sea change in America's drug policy.
Referring to the GOP's tough-on-crime heritage that he's swimming against, Johnson said, "I think that inevitably a Republican is going to have to solve this."
So far this campaign season, that day looks far off.