Mr. Paul was supposed to be a memory by now. But in the Oregon primary last week, he won 15 percent of the vote, and the campaign appears to be growing into something beyond a conventional protest campaign. Some supporters have helped turn the outspoken congressman’s campaign into a colorful, loud sideshow with their guerrilla marketing tactics — self-penned Ron Paul anthems on YouTube, a Ron Paul blimp, T-shirts that portray Mr. Paul as a world-historical icon like Che Guevara.

“Man, I’ve straight hated politics, I’ve just never liked the authority,” explained Tommy Rayome, 19, a “musician-slash-cook-slash-whatever” from Lexington, Ky., who was one of more than 600 people who showed up at last week’s Ron Paul signing at a Borders bookstore in Louisville.