This is accomplished by recycling an offhand comment that then-candidate Bloomberg made on the campaign trail last year. When asked by New York Magazine whether he’d ever smoked pot-a question which, by the way, seems hoary and desperate nowadays, like asking a candidate if he’s ever had an affair (puh leeze)-Bloomberg answered honestly, “You bet I did. And I enjoyed it.”

At the time, the remark didn’t hurt Bloomberg’s campaign. In fact, it was barely followed-up by the New York press corps-which contains more ex-stoners than there are at a Phish concert in Berkeley.

The NORML ad doesn’t suggest that Gracie Mansion is now a crackhouse; its goal is only to point out that if the mayor of New York City-a stiff billionaire who would look as comfortable in tie-dyed clothing as Wavy Gravy would in a suit-has indulged in a little of the wacky weed, then, logically speaking, everyone on the planet must be firing up bongs nightly.

“Smoking marijuana is extraordinarily commonplace,” contended Keith Stroup, executive director and co-founder of NORML. “The mayor of New York, the governor of New York, Supreme Court Justice Clarence Thomas. These are not people with wasted lives.” (Unless you count Thomas, that is; I still think he hasn’t reached his true calling: reviewing porn movies for Penthouse.)

Bloomberg’s ill-considered drug “endorsement” gave NORML just the opening it needed-an opportunity that never seemed to present itself under New York’s prior mayor, the opera-loving, defiantly anti-fun Rudy Giuliani. As New York Times columnist Clyde Haberman rightly described him the other day, Giuliani always “comes across as someone who got a briefcase for his 12th birthday-and loved it.”

So not only hadn’t Rudy had hash with his eggs, he targeted marijuana users. Under Giuliani, the NYPD arrested 52,000 people for possession in 2001, up from just 2,000 the year before he took office.

Of course, now that Bloomberg is mayor, he can’t really go around town regaling his constituents about the sheer bliss of smoking a bowl. In fact, the other day, Hizzoner felt the need to distance himself from his prior drug use. Here is the belabored explanation Bloomberg gave for his pot-smoking (and, in case you’re not a native speaker of Clintonian, I’ve provided parenthetical annotations):

“What I said back then was the truth (whoops, not the truth about enjoying pot, but the truth that I smoked it). In terms of, I had, certainly when I was younger (but not now! Oh, God, not now! And not in more than ten years! The stuff wears off! I swear it wears off!), as I suppose most people in my generation, experimented (see? It wasn’t ME, it was the TIMES! And it was a controlled experiment, not just a jam session with Bob Marley’s pharmacist! It was all in the name of science! We had a grant!). I never lie (see? I’m like George Freakin’ Washington here!), so if somebody asked me a question, I told them … Using drugs is probably a terrible idea (it really is. I mean, look at me; I used drugs and I’m only worth $4 billion and mayor of the biggest city in the country) … and I am very much in favor of enforcing laws on the books (and I would turn myself in to the 19th Precinct immediately if the damn statute of limitations hadn’t expired).”

Bloomberg’s retroactive case of regret is contagious. Not to be outdone, the speaker of the New York City Council, Gifford Miller, also admitted that he’d smoked pot-although Miller quickly added that he did not enjoy it. (So much for his chances of becoming mayor.)

With politicians coming down with regret like stoners come down with the munchies, I couldn’t help but wonder what the big deal is. (Full disclosure: Mom, I never got high when I was in college, although I once smoked a clove cigarette and found myself running around campus in a white angora sweater. You had to be there.)

Using the government’s own statistics, 76 million Americans have toked in their lives and 19 million got wicked baked as recently as last year. And many polls show that most Americans think that arresting hundreds of thousands of pot smokers every year is not a good use of police resources.

But if politicians’ all regret their prior drug use, perhaps they were just mirroring their constituents. Perhaps those 76 million Americans are sitting home wringing their hands all night long about their youthful transgressions.

To find out, I started making random calls. It turns out, the only thing people regretted was not mowing enough grass when they were younger.

“I was such a nerd when I was a kid,” said one random American. “I didn’t even try pot. I should have. I mean, at the very least, I would’ve gotten laid more, right?” (Full disclosure: Considering my strikeout-to-home-run ratio in college, I could not answer this question.)

Another random American expressed similar regret that he’d never harvested hemp. “I was such a loser in college that I was afraid,” he said. “I had no friends, either.”

Not that this column wants to suggest that illicit drug use is a sure way to have a vibrant social life in college, but, who are we kidding, it is.

It certainly worked for a nice Jewish boy named Michael Bloomberg-and he got pretty high in life, didn’t he?