Gap Inc. announced yesterday that its president and chief executive, Paul Pressler, is resigning from the company. Chairman Robert Fisher will serve as the clothing retailer’s interim president and CEO while it searches for a replacement, Gap said in a statement.

The move comes on the heels of a poor holiday season for the company and much tinkering with its advertising strategy. Gap’s recent “Peace Love Gap” campaign, designed, the company said, to promote “the importance of spreading peace and love” during the holiday season, failed to boost its sagging sales, which fell in 28 of the past 31 months.

The “Peace” advertisements followed a splashy, cause-related marketing campaign, launched in October, that promoted a line of clothing Gap developed in partnership with an AIDS relief organization co-founded by U2 frontman Bono (RED). Those ads featured earnest yet glamorous celebrities including Penelope Cruz and Christy Turlington clad in Gap clothing, letting consumers know that buying a Gap T-shirt could change the world.

Gap’s holiday ads were part of an emerging trend of advertisers using symbols and iconography with political overtones, a professor of marketing at the University of Wisconsin at Madison and a former executive at the advertising agency J. Walter Thompson, Aric Rindfleisch, said.

“This is part of a larger issue of brands being a powerful badge that represents many aspects of an individual’s life,” including political identity, Mr. Rindfleisch said.

Another such ad is Chevrolet’s ubiquitous Silverado truck commercial, which features American vistas and a John Mellencamp tune in an apparent appeal to consumers’ patriotism.

But these ads, with their politically ambiguous symbols and imagery, can be fraught with risk, Mr. Rindfleisch said, especially considering that “political divisions in this country are sharper than ever.”

The professor and fellow researchers at the University of Wisconsin have found that consumers increasingly choose brands that allow them to express their politics, not just their lifestyle and socioeconomic status.

Mr. Rindfleisch pointed to the outerwear company Patagonia’s pledge that all of its clothing will be biodegradable by 2009 as an effort to appeal to people who see themselves as ecologically responsible. “It’s like choosing a niche,” he said, albeit one that comes with the risk of alienating part of a company’s potential customer base.

But Gap’s “Peace” campaign failed to generate much controversy, despite a hypercautious environment in which NBC declined to air ads for the documentary “Shut Up and Sing,” which detailed the country music group Dixie Chicks’s contretemps with President Bush.

Consumers may well have decided that the Gap ad was as innocuous as the 1970s ad “I’d like to buy the world a Coke,” with its images of holiday peace. (Still, both the rapper Common, seen performing on a 40-foot gold peace sign in the Gap ads, and Mr. Mellencamp faced criticism for signing on.)

Judging from reactions in the blogosphere, the absence of certain symbols caused a greater stir. One poster on the Adfreak Web log complained of the absence of a Christmas tree in any of the ads.

The Gap and Chevrolet ads will not be the last to state or insinuate political positions, Mr. Rindfleisch said. So long as consumers feel that “I know who I am from what I buy,” advertisers will seek to appeal to their political sensibilities.

But while the jury is out on the effectiveness of the Chevrolet spot, the Gap ads did not get consumers into stores. Gap reported an 8% decline in sales in December, triggering the current round of executive departures amid speculation the company is putting itself up for sale.