You’ve heard of profiling criminals, but welcome to fashion profiling — the practice of classifying and targeting individuals based on their clothing brand preferences. Fashion profiling played a bigger role in the 2016 American presidential election than anyone realized, according to new information from Christopher Wylie, the Cambridge Analytica whistle-blower.

Today at a conference in Britain organized by the fashion industry website The Business of Fashion, Mr. Wylie explained that clothing preferences were a key metric for Cambridge Analytica, whose business was constructing and selling voter profiles drawn from Facebook data.

“Fashion data was used to build AI models to help Steve Bannon build his insurgency and build the alt-right,” he said.

Preferences in clothing and music are the leading indicators of political leaning, he said. The narratives of the great American brands, which play on the myths of the West and the (mostly male) frontier are also the narratives of the Republican right. Those who choose to spend on the former are susceptible to the latter. He mentioned Wrangler and L.L. Bean in particular as brands that Cambridge Analytica aligned with conservative traits. (Kenzo, by contrast, which is designed by Humberto Leon and Carol Lim, the avant-garde duo behind the retail store Opening Ceremony, appealed to liberals, he suggested.)