Illustration by André Carrilho

By the time you read this, the Thanksgiving holiday will be over, and the state of the debate over porn machines and pat-downs—a.k.a. the TSA’s new and wildly controversial airport screening procedures—may have shifted from where it stood beforehand. Perhaps the National Opt-Out Day protest will have backfired or merely fizzled. Perhaps the TSA will have managed to escape the long weekend without creating any more priceless don’t-touch-my-junk YouTube moments. Perhaps the public outcry against the enhanced-security regime will be slowly receding, like Turkey Day itself, into our collective rearview mirror.

Certainly that’s the outcome the Obama administration is hoping for—and, indeed, expecting. Last week, as the president’s people pushed back hard against criticisms of the new full-body scanners and heavy-petting pat-downs, they were also arguing that the degree of outrage had been exaggerated, the product of a slow news week and the media’s ravenous appetite for any semi-respectable excuse for talking about genitalia. And certainly history suggests that the Obamans may be right. In the years since 9/11, every incremental increase in transportation security, no matter how ridiculous or reactive, has been met with the same response: initial grumbling followed by grudging acquiescence.

But this time has been different, to put it mildly, and different in ways that suggest the furor will not soon be fading. Out of nowhere, what’s emerged is a remarkable political backlash, driven both by populist chagrin and elite disapproval, uniting the civil-libertarian left, the anti-government right, and the technocratic center. Important congressmen of both parties have written letters to TSA chief John Pistole to express concern about and suggest modifications to the new procedures. And although support for those procedures started high, it appears to be falling fast.

It’s possible that I’ll come to regret this prediction, but here goes: Between now and Christmas, the administration and the TSA will cave. This in itself would be a real victory, since the new protocols are genuinely demeaning and largely pointless exercises in what the security guru Bruce Schneier calls “security theater.” But if we’re lucky—and it’s a very big if, I’ll grant you—the entire episode may serve an even greater purpose: to start an adult conversation about the policies we adopt to reduce the risk of terrorist incidents in this country, and the foolishness of believing that any of them will lead to perfect safety.

The strangeness of the bedfellows bound together by the anti-body-scan, anti-junk-touching cause can hardly be overstated. On Capitol Hill, staunch Democratic liberals such as congresswoman Sheila Jackson Lee are on the same side as conservative Republican representative John Mica, incoming chair of the House Committee on Transportation and Infrastructure. Center-lefty writers such as Jim Fallows and Jeffrey Goldberg find themselves in agreement with the likes of Charles Krauthammer and Mark Steyn. Bloggers at Firedoglake.com and the Huffington Post are locked in common cause with Rush Limbaugh, who recently offered an incomparable cri de coeur on the topic: “Keep your hands off my tea bag, Mr. President!”

As Limbaugh’s injunction illustrates, much of the agitation directed toward the TSA is focused on the pat-down process. Yet many opponents find the full-body X-ray machines even more problematic, in part because vastly more people will be subjected to them than the newly intimate frisking (which is reserved for those who opt out of the scanners). Though the TSA initially said the machines would only be used for secondary screening, 385 of them are being employed for primary screening in 68 airports, with 1,000 units scheduled to be installed by the end of next year. That the full-body scanners expose their subjects to radiation has raised health concerns among some academics. But the greater objection is that, because they produce startlingly graphic images of those inside them, they are in effect indiscriminately inflicting on travelers a virtual strip search.

But even for people willing to set aside civil-liberties concerns in the cause of airline safety, the porn-machine/pat-down rigmarole presents another problem: ineffectiveness. As Goldberg has written on his blog at TheAtlantic.com, while the new procedures might catch someone carrying an explosive on his person, à la the Underwear Bomber, they would do nothing to detect someone with a bomb inside his person (i.e., a cavity bomb). Rafi Sela—the former chief security officer for the Israel Airport Authority, who helped design the storied system at Ben Gurion International—has gone further, telling a group of Canadian M.P.’s, “I don’t know why everybody is running to buy these expensive and useless machines. I can overcome the body scanners with enough explosives to bring down a Boeing 747.”

Even more to the point, the scan-and-grope approach represents an object lesson in the futile tendency toward fighting the last war. As Bruce Schneier put it pithily the other day on NYTimes.com, “We screen for guns and bombs, so the terrorists use box cutters. We confiscate box cutters and corkscrews, so they put explosives in their sneakers. We screen footwear, so they try to use liquids. We confiscate liquids, so they put PETN bombs in their underwear. We roll out full-body scanners, even though they wouldn’t have caught the Underwear Bomber, so they put a bomb in a printer cartridge. We ban printer cartridges over sixteen ounces—the level of magical thinking here is amazing—and they’re going to do something else. This is a stupid game, and we should stop playing it.”

Does the public understand all this? Of course not. Is it willing to give up a degree—perhaps a great degree—of personal liberty if it’s assured that doing so is the only route to safety? Yes, it is. Yet there are signs that the public is losing faith in such assurances, and in particular that support for the new TSA procedures is less robust than many believe. In a CBS News poll in mid-November, 81 percent of respondents said they were in favor of the full-body scanners. Just one week later, an ABC News–Washington Post poll found that the percentage saying the same thing had slipped seventeen points, to 64 percent. A few days after that, a less precisely worded Zogby poll found that 61 percent opposed the combination of scanners and pat-downs, with 52 percent saying the new procedures would not prevent terrorist activity.

One easy explanation for this slide is that the wave of publicity about the new TSA procedures—the headline-grabbing stories about nuns being groped or a bladder-cancer survivor being soaked in his own urine after an especially idiotic pat-down—has created a momentary bout of hysteria. But a better one is that the ebbing of trust in the TSA is the cumulative result of nearly a decade of steadily building tension and irritation. Of a growing belief that the rules being laid down are capricious, arbitrary, and mostly useless. Of an inchoate but real sense that the system is more about the appearance of safety than actual safety—the very definition of what Schneier is getting at with his term “security theater.”

And, as it happens, that is true. According to most experts in the field, very few of the supposed security enhancements adopted after 9/11 have made airline travel appreciably safer. (The two exceptions that Schneier cites: reinforcing cockpit doors and encouraging passengers to fight back in the case of a hijacking.) Which reforms would actually make transportation safer? Screening checked bags and cargo rigorously, along with the backgrounds of airport employees. Behavioral—not racial or ethnic or religious—profiling. Investing vastly more in intelligence-gathering and investigation, in breaking up terror cells abroad. Doing everything possible, in other words, to stop terror plots and plotters before they reach the airport (or any other target).

The problem with all of these strategies, however, is political. For any elected official, and especially a president, there is a huge incentive to constantly be demonstrating in visible ways that the government is doing everything in its power to combat terrorism. And there is an equally massive disincentive ever to roll back any new form of security, no matter how pointless or cost-ineffective it proves to be—for the moment an act of terror occurs, the one certainty is that the blame game will begin, with a vengeance. In truth, the formulation of security policy is a matter of balancing risks. But given the political environment, no public figure dare speak of it that way. “Politicians can’t come out and say that any risk is acceptable,” writes Fallows. “Nor can they take the risk themselves of saying that security-theater rituals should be dropped, because of the risk of being blamed when the next attack occurs. Thus security theater is a ratchet. You can add it, but you can’t take it away.”

In the coming weeks, we will see whether this is true when it comes to the scan-and-frisk regime. In truth, the TSA in the past has quietly rolled back various rules: the prohibition on carrying lighters aboard aircraft was scrapped in 2007, and today the limits on liquids are only enforced sporadically. But never before has the agency or White House behind it faced the kind of public pressure that is in play right now. As Obama and his people consider their alternatives, the political logic of security theater will no doubt weigh heavily on their minds. But they should realize that the audience is getting restless, and that what’s happened in the past few weeks may signal a readiness for a different, and more honest, kind of performance from the stage.

E-mail: jheilemann@gmail.com.