WASHINGTON -- Americans have given up a lot in the name of increased security. Intrusive and expensive measures adopted since 9/11 have eroded privacy, made air travel arduous, and turned public buildings into bunkers -- at a cost of something like a half-trillion dollars.
But when it comes to individual rights or reasonable expectations that Congress considers negotiable in the pursuit of safety, the ability to purchase military-level firepower seems off the table.
"There is something wrong when one person can get pulled aside at the airport because he left a couple of paper clips in his pocket, while someone else can buy thousands of rounds of ammunition online without anyone noticing," said Marc Rotenberg, executive director of the Electronic Privacy Information Center, a civil libertarian group.
Thanks to devoted lobbying by the National Rifle Association, and the Republican Party's use of guns as a highly politicized wedge issue, even the feeblest attempts at restricting weaponry are dead on arrival in Washington.
The very idea of banning military-style assault weapons or high-capacity magazines -- such as the ones used in the Aurora, Colo., Batman shooting on Friday -- is way more politically fraught than, say, letting the government secretly spy on citizens without a warrant.
Even people on the U.S. government's terror watch list can still buy guns, thanks to the GOP.
In contrast, many of the steps taken by the Department of Homeland Security -- and particularly its Transportation Security Administration -- have been widely criticized as ineffective.
Forcing air passengers to take off their shoes, for instance, is "based on securing a particular tactic, when switching tactics is easy," said Bruce Schneier, a private security technologist and author. "The next guy put the bomb in his underwear," he noted.
One team of economists calculated that onerous security screening has led more people to drive in cars rather than deal with airports, resulting in some 500 more traffic deaths annually.
Airport security measures "make it marginally harder for terrorists to go in and blow up a plane in flight," said Charles Perrow, a Yale University sociology professor emeritus who has called the creation of DHS "The Disaster After 9/11". "But we have very few of those incidents, compared to what we spend to prevent them. The response is totally inappropriate.
"We lose 11,000 people a year from weapons. We lose practically zero a year from terrorist attacks," Perrow said.
Meanwhile, as far as Perrow is concerned, there's no real cost associated with banning weapons that have no practical purpose other than mass shooting.
So technically, that's an infinite cost-to-benefit ratio. "You don't get that very often," Perrow said.
Restricting military-style weapons sales certainly has common sense going for it. "It seems pretty obvious to me and a lot of other people, if you don't allow people to buy this stuff, they can't use this stuff," Schneier said.
"But in this country, you cannot have a rational security debate that involves guns," Schneier said. "The politics is so great that any analysis is ignored by half the population."
Perrow said President Barack Obama missed a key opportunity a few months into office when he failed to support a Democratic bill that would have reinstated a ban on assault weapons that the Bush administration let expire.
"I just think that was cowardice on Obama's part," Perrow said.
Ohio State University professor John Mueller wrote in a recent book that DHS focuses way too much attention on terrorist attacks and way too little on common occurrences.
Those include such things as hurricanes, tornadoes -- and mass shootings.
Mueller's estimate of a half-trillion dollars in federal spending for increased security is only the half of it. He and his coauthor estimate that when you add private sector costs and "opportunity costs" of delays and inconveniences, the increased spending in the U.S. exceeds $1 trillion.
Such enhanced expenditures would be cost-effective only if a 9/11-scale attack would have occurred more than once a year without them, they concluded.
"What people have given up is some degree of privacy, and convenience, and obviously tax money," Mueller told HuffPost. "That's a lot of money."
Meanwhile, shootings involving high-powered weapons, high-capacity magazines and multiple victims have become nearly commonplace. The Brady Campaign to Prevent Gun Violence maintains a list of mass shootings since 2005 that is 62 pages long -- and counting.