Just five years after Mayor Giuliani offended liberal orthodoxy by daring to ask why the taxpayers should subsidize an exhibit at the Brooklyn Museum of Art that included, among other things, a depiction of the Virgin Mary decorated with elephant dung and explicit crotch shots from porn magazines, here we go again.

At the Smack Mellon studio in the Dumbo section of Brooklyn, in an exhibit that came down this Sunday, an artist stacked some old Playboy and Club soft-core porn magazines on a coffee table, put a few pinup posters of Farah Fawcett and Bo Derek on the wall, and played an hour-long video of tennis great Bjorn Borg playing a match with a cross-dressing lookalike version of himself. Visitors to the gallery, who could have been of any age, could sit on a couch and leaf through the magazines — after passing a big sign reminding them that the whole spectacle was thanks to the generous support of the National Endowment for the Arts and the New York City Department of Cultural Affairs. In other words, it was paid for with your tax dollars.

It looks like columnist William Safire of the New York Times might have been a little premature when he wrote Monday, “Remember the hoo-ha a while back about the funding of edgy art, offensive to some taxpayers, by the National Endowment of the Arts? That controversy is over. The N.E.A. has raised a banner of education and accessibility to which liberal and conservative can repair.”

The reaction so far of the government agencies responsible has been disappointing. “It is not surprising that of the city’s thousands and thousands of exhibits and performances, someone will be offended by something,” said the city’s commissioner of cultural affairs, Kate Levin. She claimed the issue is “moot”because the show closed on Sunday.

Well, not exactly. If Ms. Levin won’t even acknowledge that there was something inappropriate about the city, in the middle of a budget crisis, taxing its citizens $6,000 to subsidize this pornography den, what’s to stop it from happening again?

One reason New Yorkers are paying the highest combined state and local tax rates is the culture of government officials who refuse to acknowledge such foolish expenditures could be cut. When the cuts came, the Bloomberg administration closed fire houses and laid off school employees. But they somehow managed to preserve the porn budget.

The National Endowment for the Arts, which sank $20,000 into Smack Mellon in 2004, likewise throws up its hands. “We can’t be responsible for everything that we do,” an NEA spokeswoman, Victoria Hutter, told our Jacob Gershman in one of the most remarkable abdications of responsibility ever uttered by a custodian of public funds. The NEA claimed yesterday it had been misquoted, but its other explanation — that it had funded the gallery, not the porn exhibit — is a kind of artistic sophistry that misses the point.

With an attitude like that, Congress would be wise to take a hard, skeptical look at President Bush’s request for an $18 million increase in annual funding for the NEA, which would be the endowment’s largest annual increase since 1984.

It is now clear that, in the wake of the Brooklyn Museum uproar, the city missed an opportunity to create reasonable community standards for doling out cash to cultural institutions. When running for mayor, Michael Bloomberg signaled that he wouldn’t be so gauche as to mess with the city’s arts establishment. His administration has toed the line accordingly.

Artists have the right to create whatever they want, including work that tantalizes or shocks. Great creative minds throughout history have offended mainstream sensibilities, and, thankfully, many have brought that energy to the streets of New York. But the First Amendment to the Constitution reads “Congress shall make no law…abridging” freedom of speech, not “Congress shall spare no quarter promoting” it. So no one is entitled to public money to produce artwork that many taxpayers may consider offensive or just plain bad.

But that’s exactly what happens. The federal NEA gives out some $100 million in grant money every year, about 60% of which goes to nonprofit groups and about 40% of which goes to state and regional arts organizations. New York City’s Department of Cultural Affairs also has a generous annual budget — $120 million — and a capital budget about twice that. Most of that $120 million helps run the 34 city-owned cultural institutions; about $17 million a year goes to individual cultural groups like Smack Mellon.

Much of this spending no doubt goes to support institutions that are almost universally admired for genuine excellence, like the Metropolitan Museum of Art. But lavishing public funds on pornography only undermines public support for more worthwhile spending on arts and culture by eroding the credibility of the government officials in charge of spending the money.

Taxpayers in the end figure they’d rather have lower taxes, and decide themselves whether to donate the money to the Met or go to the newsstand on the corner and pick up some porn magazines.

There is one unintended side effect. Watching liberals and government officials in Republican administrations defend this kind of spending is priceless performance art.