In 1992, when Jay Leno took over from Johnny Carson on The Tonight Show, he was already a familiar presence, having served as one of Carson's regular substitute hosts. Despite that experience, Leno's first few years on Tonight were rocky.
"When he started, when he was up against Letterman, Letterman beat him for the first couple of years," critic David Bianculli tells Fresh Air's Terry Gross. "But once Leno came ahead, he was unstoppable. He never lost that audience."