Want to hear from your doctor on patriotism? On regulations run amok? On President Obama? Then turn to Fox News.

In a well-timed send up of the network’s clever reliance on medical “experts” who adore veering into non-medical topics, Jon Stewart of “The Daily Show” ripped away: “Medical advice isn’t really the focus of Fox’s medical experts. They serve a much more important purpose — to agree with Fox News talking points. For example, say the president wants everyone to have insurance. Who better to say that’s a bad idea than a doctor?”

At which point, Stewart skipped to a clip from Fox News medical contributor Dr. Marc Siegel: “Before they started this, we were all in trouble with insurance to begin with. There’s too much health insurance. It covers too much. Too many people have it,” said Siegel. Stewart gave the guy credit for originality: “Congratulations, I’ve never heard that before.”

Stewart’s verdict comports with the impressions of any half-awake Fox News viewer: “These guys seem less like doctors and more like the shady expert witnesses paid by the defense to say that the bullet hole exit wound — I don’t know, maybe that’s a third nipple,” joked the host.

This attack on Fox News’s medical advisers is more than just fun and games, however; there’s a larger point in there about mainstream journalism. Take a look at Siegel’s credentials: A bio on FoxNews.com lists him as associate professor of medicine at NYU Langone Medical Center He went to SUNY Buffalo School of Medicine & Biomedical Sciences and did his residency training at the New York University Medical Center.

Which is to say, the guy has bona fides, except when he’s on Fox News and saying precisely the stuff that his handlers want him to say. This is common practice. Journalists frequently lace their work with the words of experts who sense why they’re being consulted. Want a climate-change skeptic? There are plenty of those at the ready with well-honed talking points. A climate-change alarmist? Same thing. To journalists, experts are commonly not experts at all, just channelers of the prejudices of the reporters they’re talking to.

Think back to 2002, when the Associated Press busted Washington reporter Christopher Newton for having made up all manner of experts in at least 40 stories — and quoting them. Then-Slate media critic Jack Shafer wrote:

Every day, thousands of reporters pad their stories to fit the stock news formula. Like casting agents, they phone around looking for the precise quotation their story needs to appear “balanced.” They lead their witnesses with language such as, “So would you say …?” or asking the question five different ways until they get the right quotation to fit their predetermined thesis and complete the formula. If it’s a journalistic crime for Christopher Newton to invent characters who mouth empty but passable clichés, what’s the name of the offense when respectable reporters deliberately harvest the same worthless clichés from bona fide sources?

Now back to the frivolous. Apparently Stewart & Co. had plenty of jokes on the medical folks, such that they saw no need to highlight how Fox News’s Dr. Manny Alvarez had chosen to spell a common human affliction:

(Daily Show screenshot)

RELATED: The worst media screw-ups of 2013