The federal government shutdown, the debt ceiling showdown and the so-called Patient Protection and Affordable Care Act are serious matters.

But those objects of public debate are also fodder for the comic relief Jon Stewart airs nightly on “The Daily Show.”

And though the liberal host launches most of his sarcastic barbs at conservatives, he aimed on-target ridicule at U.S. Health and Human Services Secretary Kathleen Sebelius while interviewing her Monday night.

Mr. Stewart started the segment by pulling out a laptop computer and telling the plainly chagrined Ms. Sebelius: “We’re going to do a challenge. I’m going to try and download every movie ever made and you are going to try to sign up for Obamacare — and we’ll see which happens first.”

What happened next was a series of fair questions from Mr. Stewart, and evasive answers from the secretary.

Ms. Sebelius conceded that the website where Americans are supposed to sign up for insurance under the law has been a mess. When asked how many people had enrolled on the site since it supposedly became available on Oct. 1, she said she didn’t know.

That was embarrassing enough for the HHS secretary.

Then it got worse for her — and the administration.

Mr. Stewart decried the White House’s decision to postpone the mandate requiring businesses with 50 or more employees to provide health insurance to them: “If I’m an individual that doesn’t want it, it would be hard for me to look at a big business getting a waiver and not having to do it and me having to.”

After inartful dodging by Ms. Sebelius, Mr. Stewart asked: “Let me ask you this — am I a stupid man?”

No, he’s not.

Yet like too many other Americans, Mr. Stewart has been slow to spot the folly of Obamacare.

But at the end of Monday night’s show, long after Ms. Sebelius had left the stage, Mr. Stewart gave this withering conclusion on Ms. Sebelius’ failure to effectively defend the double standard on the business and individual mandates: “And then I think to myself, ‘Well, maybe she’s just lying to me.’ ”

There’s no “maybe,” though, about this law being pitched on false pretenses.

The president, while pushing the bewildering legislation through Congress without a single Republican vote, repeatedly said that it would let people who liked their insurance plans keep them as they were. He also said the law would produce widespread reductions in insurance rates — and a widespread increase in the number of Americans with health insurance.

None of those assurances has been fulfilled.

Meanwhile, the law has predictably powered a shift toward more part-time — and fewer full-time — workers by employers wary of the law’s burdens. Ms. Sebelius further undermined her credibility by denying that obvious side-effect Monday night.

As for that mess of a website, Luke Chung, an online database programmer who supports Obamacare, told CBS News: “I would be ashamed and embarrassed if my organization delivered something like that.”

And Obamacare’s fundamental flaws go far beyond the ongoing cyber-debacle in this latest rollout.

Yes, Republican lawmakers have foolishly created a distraction from the law’s shortcomings with their ill-advised, futile attempt to “defund” it, a strategy that triggered the ongoing federal shutdown.

But they’re not the ones blocking Obamacare at this point.

President Obama is, by issuing self-serving edicts delaying many of the law’s most onerous consequences beyond next year’s congressional elections.

The good news Thursday was that the GOP House and the president appeared to be moving toward a deal to raise the debt ceiling.

The bad news is that the Affordable Care Act, with or without a workable website, remains an unaffordable law.

And that’s no laughing matter.