Between 13 million and 16 million Latinos are expected to vote in this year’s presidential election. And many of those voters can thank San Antonio native Willie Velasquez when they cast their ballots. This hour, we’ll talk about the founder of the Southwest Voter Registration and Education Project, who launched more than a thousand voter registration drives in the 1970s and ’80s. We’ll be joined by Hector Galán, director of the PBS documentary “Willie Velasquez: Your Vote Is Your Voice,” which airs Oct. 3 on KERA-TV. KERA will also host special advance screenings of the film in Dallas on Thursday and Fort Worth on Sept. 29.