In a pair of town houses less than 10 blocks from where the Supreme Court gave his group a place in legal history, David Bossie is making movies and cutting a path for a new art form: the nonpolitical political ad.

Bossie is the president of Citizens United, a conservative group whose anti-Hillary Clinton movie in 2008 led to a landmark ruling this year. The Supreme Court threw out parts of a 63-year-old law prohibiting corporations and unions from paying to air ads for or against political candidates.