One lesson of Washington's non-panic over the imminent shutdown of the Department of Homeland Security: the 9/11 era is over.

Set your Hot Tub Time Machine back a decade and this week's political brinksmanship is unthinkable: Congress would sooner cut funding to the Puppies for Veteran Grandmothers program than to the Department of Homeland Security. Republicans won the 2002 election simply by arguing that Democrats, who initially came up with the (terrible) plan to create the DHS, didn't support their own idea fervently enough. In the 9/11 era, any federal program that so much as brushed against national security was sacrosanct.

A decade later, Republicans angry over President Obama's immigration actions decided to retaliate by holding all DHS funding hostage. And now that we're days away from Congress actually cutting off funding for the Department of Homeland Security, there's little alarm in Washington. That's true even though the terror group Al-Shabaab is threatening to launch attacks against American malls.

Imagine reading those last two sentences in 2004. Imagine how strange they would sound.

To be fair, a DHS shutdown isn't quite as scary as it sounds. Because so many DHS employees' jobs are paid for by fees or multiyear appropriations and because so many of the remainder have positions that are classified as saving lives or protecting property, about 85 percent of DHS workers keep coming to work amidst a shutdown.

But even so, no agency runs smoothly amidst the chaos of a partial shutdown. And DHS is no exception. If you want a department operating at peak efficiency, you don't cut off its funding and furlough a bunch of its workers. And, a couple of years ago, it would have been inconceivable that anyone would permit DHS to operate at anything less than peak efficiency — that any politician, to put it bluntly, would put themselves in position of distracting the Department of Homeland Security from preventing the next terror attack.

To be fair, the GOP's dwindling war caucus is concerned. "I’ve never seen more terrorist organizations … that want to strike the homeland than I do today, and that’s a direct result of a failed foreign policy by President Obama," Sen. Lindsey Graham said on ABC’s "This Week." "And the worst thing to do is having the Republican Party add gasoline to the fire by defunding the Department of Homeland Security."

Graham's colleague, Sen. John McCain, is beating a similar drum. But few in their party seem to be listening. DHS is no longer protected from the vagaries of politics simply because it has the words "homeland security" in the name. Neither the optics nor the reality of partially shutting down the agency strike Republicans as particularly disastrous.

It's as good a proof as any that the 9/11 era in American politics is well and truly over.