Museums requiring socially responsible art know they can count on Carrie Mae Weems. A longtime polemicist who relies heavily on historical documents and re-enactments, Weems has produced projects commemorating the Louisiana Purchase bicentennial and the birthplace of author Zora Neale Hurston. In each, the artist delivered elaborate works of high-end production value and didacticism.

So I guess I shouldn't have been surprised when I walked into G Fine Art last weekend and wondered if I'd got the address wrong. Had I wandered into the National Museum of American History by mistake? Passing through the artist's solo installation, "The Jefferson Suite," was akin to a walk through one of the Smithsonian's more pedantic exhibitions. And it was not a good thing.

The photo-based works Weems has turned out since gaining artistic traction in the early 1990s (the artist is in her early fifties now) have explored the black experience of slavery and assimilation, along with women's changing social roles. As in "The Jefferson Suite" -- more about the meaning of the title in a moment -- the artist appears in many of her pieces, often in the guise of historical figures. Her works mix historic and contemporary imagery, often coupled with text. As with artists Cindy Sherman and Nikki S. Lee, who also appear as characters in their photo-based work, Weems's starring role in these narratives allows her to reenact scenes, with liberal artistic license, in order to point out societal contradictions and injustices.

"The Jefferson Suite," commissioned by the Santa Barbara Museum of Art in 1999, is just such a work. In it, Weems has folded 21st-century arguments about scientific research into issues of African American discrimination. The lesson we're to glean: Genetic engineering and gene mapping are problematic advances, for whites as well as blacks.

At G, the setup is educational in the manner of museum shows. Billowy scrims emblazoned with photographs and suspended from the gallery ceiling in recessive rows deliver a walking slide show of historical images. As we navigate the larger-than-life portrait gallery, a voice-over narration, delivered by the artist, intones a prose-poem directed at genetic engineers. Alternately citing successes and failures, she points increasingly accusatory fingers at scientists and their moneyed (read: greedy) financial backers: "blinded by the rigors of your own capacity, you forged into and beyond the age of reason, trading in human flesh, bankrolling junk bonds and junk genes."

At no time is it difficult to tell which side we're supposed to be on. Just in case we don't know, though, Weems has inserted a soundtrack of mournful music in the background, which swells as particularly serious passages are read. She's also added a wall of large-scale photos of sitters (of varied skin colors) with their backs to us, each emblazoned with a large letter -- T, A, G or C -- which stands for one of the nucleotides of DNA. No matter our skin color, these pictures seem to be saying, we are all made up of the same genetic code. It is our great equalizer.

The image narrative opens with a picture of Weems herself, dressed like Billie Holiday and standing at a microphone. Pictures of the Busch Quartet, an early 20th-century chamber group noted for its anti-fascist politics, hang behind her. From the get-go, a liberal agenda has been established.

The scrims beyond are each emblazoned with figures and scenes -- of Charles Darwin, of a goldfinch, of a gibbon and child at play, of a ticker-tape parade, of a black man in handcuffs, of a woman and her baby, of a lamb facing a gang of photographers. Each picture was chosen to cue milestones in the history of genetic engineering, yet the pictures won't all be recognizable right off. Yes, we get the Dolly reference -- Weems has superimposed a few bars of the famous ditty "Hello Dolly" on the face of the print. And we might remember Darwin from our history books, though there were lots of famous old guys in white beards. Mostly, the pictures are hard to place. So we resort to the gallery handout, which tells us more about them. "This image is representative of genomic profiteering," says the description accompanying the picture of the ticker-tape parade. That we require such detailed explicatory text to grasp the images we're looking at troubles me. It seems the piece isn't working on its own terms.

Then there is the work's final image pair. One is a photo of Weems playing Sally Hemings, the mistress of Thomas Jefferson, with all the historical cues in order: man in wig wielding feather pen, black woman in period garb. To the picture's right, another historic retelling: Here, a man in a business suit hangs on the phone as a woman in office-proper skirt and bra does a dance for him -- a scene meant to evoke Monica Lewinsky and Bill Clinton. Yes, it was DNA evidence that tied Jefferson to Hemings and Clinton to Lewinsky. Yes, it's good to know the truth about one of our founding fathers and, depending on your politics, it's either very bad or very good that the stain on that famous blue dress got analyzed. But then what?

The final pictures from "The Jefferson Suite" remind me of stills from a PBS special -- poetic and not striving particularly hard for historical accuracy. Weems's narration, punctuated by that chorus of strings, seems more eager to convey information than allow us time to think. With "The Jefferson Suite," Weems is at once too obvious and not obvious enough.

Carrie Mae Weems at G Fine Art, 926 N St. NW, Wednesday-Friday 11 a.m.-6 p.m., Saturday 11 a.m.-5 p.m., 202-333-0300, to July 31.

Carrie Mae Weems's "Jefferson Suite," left and below, at G Fine Art: Folding 21st-century arguments about scientific research into issues of African American discrimination.