If you think you can't stand reading about how the media are covering Michelle Obama's Spanish vacation, then you deserve credit for good taste.

But bear with me. Because, given the absence of any substance whatsoever, it serves as a perfect laboratory exercise in how rightwing activists bully the nominally liberal mainstream press into validating the most ludicrous of partisan talking points.

As you may know, late last week the first lady and her daughter Sasha arrived in Spain for a few days. With the exception of a government-provided security detail, the trip is costing the taxpayers nothing. Yet it has come under withering attack from the right, as critics have seized on it as evidence that the Obamas are elitist elite liberal elitists.

But there's no need for me to strain my limited vocabulary when I can simply send you to Rush Limbaugh's website, currently featuring an altered photo of "King Louie Obama & Michelle Antoinette" that looks like something from a lost episode of Good Times. In an accompanying commentary, Limbaugh explains what's going on in terms anyone can understand (provided that by "anyone" you mean, well, white racists). He says of the Obamas:

"They have never had it so good. They don't want for anything. They don't even pay for anything. In fact, they look at it as though they are owed this. They are owed this. They have been shafted all of their lives because of racial discrimination, because of being a minority."

For good measure, Limbaugh invokes Marion Barry, the former mayor of Washington, DC, for no particular reason I can think of – except maybe that Barry is black, has had several well-publicised encounters with illegal drugs and has done time.

Well, all right, you might say. Limbaugh's a loon. But times are tough, and maybe Mrs Obama should have spent some of her money on an American vacation spot. That would have mollified the critics. Right?

Wrong. Check out Bradley Bakeman, writing for Rupert Murdoch's FoxNews.com, who rips the first lady for vacationing in Spain – as well as for the family vacation the Obamas took in Maine last month, a time when oil was gushing into the Gulf of Mexico. "I guess the Obamas thought it was better to cruise the pristine waters of Frenchman's Bay than the oil-slicked waters in the Gulf," Bakeman sneers. (Bonus points for working in the subliminal reference to France. Pass the freedom fries.)

I could go on and on, but you get the idea. What really matters is the way the mainstream media have incorporated such idiotic criticism into their own coverage and commentary, starting with a New York Times story on Sunday that ran beneath a curiously passive-voice headline: "First lady's Spain vacation draws criticism".

At least the Times story notes, rather defensively, that several of the criticisms raised by Limbaugh and company are wrong (for instance, Michelle Obama is not travelling with 40 friends). But the real stupidity is unveiled on the op-ed page, where Maureen Dowd, an alleged liberal who yet never fails to take the rightwing bait, weighed in with a Sunday column that took the first lady to task for leaving the president back home in his hour of need:

"In politics and pop culture, optics are all. And Michelle's optics sent a message that likely made some in the White House and the Democratic Party wince."

Over at the Washington Post, Ruth Marcus actually defended Michelle Obama. But look more closely: Marcus devotes about two-thirds of her piece to conceding that the critics are right, but, well, they're being "unfair". Marcus begins her purported defence by writing, "Let's stipulate: A five-star resort on the Spanish Costa del Sol was probably not the first choice of White House spin-meisters for a mother-daughter getaway." Good grief.

On and on it goes. At the Atlantic's website, Megan McArdle blogs that "while there's nothing actually wrong with it, it's really quite unbelievably politically stupid." Writing for Murdoch's New York Post, Democratic political analyst and Fox contributor Kirsten Powers calls the trip "a PR gift to her husband's opposition".

Kudos to Eric Boehlert of the liberal watchdog group Media Matters for America, who's been keeping track of all this on his Twitter feed, and to his colleague Christine Schwen for puncturing the false claim that George and Laura Bush hardly spent any money on their frequent trips to Crawford, Texas; Kennebunkport, Maine; and Camp David.

In part, the criticism to which Michelle Obama is being subjected can be attributed to August foolishness, a traditionally news-free month when the media can be counted on to seize upon any ridiculous story that comes by, whether it's shark sightings or a sleazy congressman suspected, on the basis of no real evidence, that he'd murdered an intern and hidden her body somewhere in Washington.

But when these stories involve partisan politics, they rarely cut the other way. The pattern goes back decades: the right exaggerates or even manufactures a grievance, then whines that the liberal media are ignoring the story – until, finally, the so-called story is covered, usually on terms favourable to the right (think Whitewater, Climategate and Acorn). Eric Alterman, the liberal media critic for the Nation, calls it "working the refs" in his book What Liberal Media?

The kerfuffle over Michelle Obama's vacation is so silly that you might be tempted to dismiss it as a trifle that doesn't matter. Well, maybe it doesn't matter much. But it matters a little.

With Democrats desperately trying to hold on to Congress this fall against a Republican party that wants to preserve tax cuts for the rich and repeal constitutionally guaranteed citizenship rights, the last thing they need is a fake controversy that reinforces the media-driven notion that the Obamas are out-of-touch elitists.

Folks in the media, terrified of being accused of liberal bias, are being used. Sadly, there's nothing new about that.