It's a widely held misconception that judges swear an oath to uphold the law. In fact, judges swear an oath to protect and defend the Constitution.

Yes, it often works out to the same thing, since the state and federal constitutions charge the courts with enforcing the penalty provisions of law.

But not always. The exception comes when a law is unconstitutional.

Frankly, lots more laws created by our legislators should probably be tossed out for exceeding the limited powers granted to the legislative branch. Laws enacted directly by popular vote avoid that problem, but still cannot be allowed to infringe constitutional guarantees of freedom of speech and religion, "equal protection," and so forth.

Tavern owners challenged Question 5 -- the public tobacco-smoking prohibition OK'd by Nevada voters last month -- on just such grounds. They argue the measure discriminates against some tavern and restaurant owners by continuing to allow those with unlimited gaming licenses to welcome smokers.

The pragmatism of the exemption is obvious: Casinos are a powerful force in Nevada -- the tobacco prohibitionists didn't want to fight them, at least not yet.

Obviously, it would be a bad thing to allow a law to take effect before the courts have reviewed its constitutionality. It was thus right, proper and routine for District Judge Douglas Herndon to issue a temporary restraining order against enforcement of the new measure while he reviewed its constitutionality.

To some extent, the judge has now split the baby, as the saying goes. He will allow enforcement of the measure to proceed, but only as a civil offense -- no criminal charges.

But the more important question, now, is how those who consider this measure unwise should view its taking effect.

Make no mistake, the vote to ban smoking in virtually all public venues but casinos was ill-considered. Such nanny-state measures, piled one atop the other (What next? Cut off liquor service at midnight?) can't help but impinge on tourism -- this valley's lifeblood -- eventually.

The evidence that smoking tobacco damages one's health and life expectancy is solid. But if this measure were about "protecting the children," as advertised, why not give tavern owners the option of barring tobacco smoke, or barring children? Why not require barriers and ventilation to make non-smoking areas truly smoke-free by some measurable standard?

The absence of such options reveals the Prohibitionist soul of Question 5. Neither patrons nor business owners can be allowed any "choice" in what legal behaviors will be allowed: After all, they might make the "wrong" choice.

We used to joke, "What will they try to ban next? Milk shakes and fries, because it's unhealthy to be fat?" But it's not wise to joke with the humor-impaired. All that's now coming down the pike, and more.

So, should we lament Judge Herndon's decision to let this measure take effect?

No. To do that -- lamenting judicial activism only when we dislike the result, encouraging such meddling when we find the result pleasing -- would be hypocritical, and a betrayal of the rule of law.

The voters spoke. Such temporary majorities (no matter how unwise) should be overruled only when their actions are blatantly offensive to the Constitution -- attempting to restore racial segregation, say, or requiring that candidates for office swear loyalty to a given church.

The majority have infringed not just the freedom of choice of smokers, but also the property rights of business owners. Do those who voted for this measure truly believe some new majority will not use this precedent to infringe some of their favorite rights and liberties, somewhere down the road?

This will come back to bite Nevadans. But it was not Judge Herndon's job to protect them from their own mistake.

"People deserve the government they get," quoth H.L. Mencken, "and they deserve to get it good and hard."