There comes a time in every critic’s life when they have to face the sad reality that shows they think are pretty vacuous are actually doing some good cultural work.

Take, for instance, “Brothers & Sisters,” which — from my very brief perusal (and testimony of trusted friends for which it is a guilty pleasure) — falls into the crisis-of-the-week schmaltzy family drama genre, even if it puts its characters in some fairly fresh situations.

But according to Rick Kushman, TV critic for The Sacramento Bee, I need to see the show — and much of pop culture in general — as a sign of significant cultural change, especially in light of the show’s complex portrayals of gay men (a commitment ceremony between two of them ended this past season) and right-wing zealots:

Put simply, pop culture — and, again, especially TV — does have influence on attitudes and ideas in America, but much more, TV reflects the ideas that have been accepted by society.

That runs counter to the arguments of the blame-TV-for-everything crowd, but it’s a near-universally agreed-upon principle among network programmers, advertisers and academics who study this sort of thing.

And in light of the California Supreme Court’s recent ruling that gay couples can marry, and with a constitutional ban on gay marriage possibly moving toward the November ballot, that notion — the idea that Americans are far more comfortable with the concept of “live and let live” than their political leaders — adds another layer to the national conversation.

The first thing that’s obvious is that TV and all of popular culture is more accepting of a broader range of images and ideas than they’ve ever been, and that includes showing gays and lesbians as fully rounded people.

That’s why The Ellen DeGeneres Show has been a top-rated daytime series for five seasons, why Brothers & Sisters is a Top 20 show, and why CBS’ soap As the World Turns started a storyline about a gay couple to draw younger viewers.

It’s of course simplistic to say that if media images are out there, then Americans are not bothered by any of them. All sorts of Americans are bothered by all sorts of media images.

But, as Syracuse University professor of popular culture Robert Thompson says, TV and movies and every part of the entertainment industry are first of all businesses. And for any show or movie to succeed, it needs to connect with a fairly mainstream audience.

“It’s not a clear calculus,” Thompson said in a phone interview. “Media and popular storytelling are doing a dance with the real world, and nobody’s leading.

“But you could make a strong argument that popular culture is a great barometer of attitudes, because it has to come out of the marketplace.”

Another example that might fit this argument is Grey’s Anatomy — which Dawn Turner Trice suggests might just be a 21st century “blueprint for colorblindness“:

The world that surrounds television’s “Grey’s Anatomy” is one in which race means nothing. The head honcho is an African-American man who once had an extramarital affair with a white surgeon. An Asian-American woman is reeling from a broken engagement to one of the country’s premiere heart surgeons, who just happens to be black (and is no longer on the show). A Hispanic woman just divorced a white man and is having a steamy, no-strings-attached relationship with another white man. And, if that’s not enough, she’s about to begin what we assume will be a steamy, no-strings-attached sexual relationship with a white woman. In Thursday’s season finale, a biracial young woman who has a brain tumor is in love with a young white guy who also has a brain tumor.

Any old mirror can reflect, of course. What matter is if these shows are ahead of the cultural and political curve — or if they are just giving America the fantasy that it wants to keep as a fantasy.

And that, as everything seems to these days, gets us back to the presidential campaign. This summer will test if the mainstream media’s fascination with Barack Obama — and the hope and dreams that he represents — is just a way to tap into an American desire to try on that hot new dress, with no intention of really buying it.