Jeff Bergman’s name may not ring a bell, but he has some very recognizable alter egos: Bugs Bunny, Sylvester the Cat and Yogi Bear, to name a few. Bergman is the voice of many of the cartoon stars of “Space Jam: A New Legacy.” His repertoire includes nearly 200 voices, including Donald Trump and Joe Biden in Showtime’s “Our Cartoon President.” He tells KCRW about some of the challenges of this often overlooked profession.