Against all odds, the stodgy old National Portrait Gallery has recently become one of the most interesting, daring institutions in Washington. Its 2009 show on Marcel Duchamp's self-portrayal was important, strange and brave. "Hide/Seek," the show about gay love that it opened in October, was crucial - a first of its kind - and courageous, as well as being full of wonderful art. My review of it was a rave.

Now the NPG, and the Smithsonian Institution it is part of, look set to come off as cowards. Tuesday, after a few hours of pressure from the Catholic League and various conservatives, it decided to remove a video by David Wojnarowicz, a gay artist who died from AIDS-related illness in 1992. As part of "Hide/Seek," the gallery was showing a four-minute excerpt from a 1987 piece titled "A Fire in My Belly," made in honor of Peter Hujar, an artist-colleague and lover of Wojnarowicz who had died of AIDS complications in 1987. And for 11 seconds of that meandering, stream-of-consciousness work (the full version is 30 minutes long) a crucifix appears onscreen with ants crawling on it. It seems such an inconsequential part of the total video that neither I nor anyone I've spoken to who saw the work remembered it at all.

But that is the portion of the video that the Catholic League has decried as "designed to insult and inflict injury and assault the sensibilities of Christians," and described as "hate speech" - despite the artist's own hopes that the passage would speak to the suffering of his dead friend. The irony is that Wojnarowicz's reading of his piece puts it smack in the middle of the great tradition of using images of Christ to speak about the suffering of all mankind. There is a long, respectable history of showing hideously grisly images of Jesus - 17th-century sculptures in the National Gallery's recent show of Spanish sacred art could not have been more gory or distressing - and Wojnarowicz's video is nothing more than a relatively tepid reworking of that imagery, in modern terms.

Until Tuesday afternoon, museum staff, under Director Martin E. Sullivan, believed that "Fire" was interesting art that made important points. And now it looks as though they're somehow saying that they were wrong about that, and that it really was unfit to be seen or shown, after all.

If every piece of art that offended some person or some group was removed from a museum, our museums might start looking empty - or would contain nothing more than pabulum. Goya's great nudes? Gone. The Inquisition called them porn.

(TIMELINE: A look back at notable art controversies)

Norman Rockwell would get the boot, too, if I believed in pulling everything that I'm offended by: I can't stand the view of America that he presents, which I feel insults a huge number of us non-mainstream folks. But I didn't call for the Smithsonian American Art Museum to pull the Rockwell show that runs through Jan. 2, just down the hall from "Hide/Seek." Rockwell and his admirers got to have their say, and his detractors, including me, got to rant about how much they hated his art. Censorship would have prevented that discussion, and that's why we don't allow it.

Rep. Eric Cantor (R-Va.) has said that taxpayer-funded museums should uphold "common standards of decency." But such "standards" don't exist, and shouldn't, in a pluralist society. My decency is your disgust, and one point of museums, and of contemporary art in general, is to test where lines get drawn and how we might want to rethink them. A great museum is a laboratory where ideas get tested, not a mausoleum full of dead thoughts and bromides.

In America no one group - and certainly no single religion - gets to declare what the rest of us should see and hear and think about. Aren't those kinds of declarations just what extremist imams get up to, in countries with less freedom?

Of course, it's pretty clear that this has almost nothing to do with religion. Eleven seconds of an ant-covered crucifix? Come on.

This fuss is about the larger topic of the show: Gay love, and images of it. The headline that ran over coverage of the matter on the right-wing Web site CNSnews.com mentioned the crucifix - but as only one item in a list of the exhibition's "shockers" that included "naked brothers kissing, genitalia and Ellen DeGeneres grabbing her breasts." (Through a bra, one might note, in an image that's less shocking than many moves by Lady Gaga.) The same site decries "a painting the Smithsonian itself describes in the show's catalog as 'homoerotic'. "

The attack is on gayness, and images of it, more than on sacrilege - even though, last I checked, many states are sanctioning gay love in marriage, and none continue to ban homosexuality.