Here comes an audacious statement. No one has influenced American television more than Norman Lear. Think about it, and you will realize it is true. Lear transformed a medium that offered us bland, suburban stories into narratives that were simultaneously funny and cutting. The 1970s unfolded through those stories — “All in the Family,” “Maude,” “The Jeffersons,” “Good Times,” “Sanford and Son.” Lear single-handedly put such issues as race, class, sexuality and bigotry before Americans. (He also invented the idea of the spinoff, which was sort of a midrashic art form, in which a relatively minor character in one story...