Satirical comedy troupe the Credibility Gap didn't enjoy significant popularity outside their native Southern California during their life span, but the group was a training ground for a number of major comic talents, including Harry Shearer, Michael McKean, and David L. Lander. The Credibility Gap's name came from a Nixon-era euphemism for the distance between a politician's statements and the truth, and began in 1968 as a regular feature on Los Angeles radio station KRLA-AM created by news director Lew Irwin. Irwin and his collaborators Richard Beebe, Thom Beck, Len Chandler...