The shocking Roots miniseries opened the year, and an All in the Family Christmas episode questioning the existence of God ended it. But what had TV in the biggest lather in 1977 was Soap, a new ABC comedy that cropped up in between.

Forty years ago this summer, the adult parody of daytime dramas, set to debut in September, had TV watchdogs threatening to wash out the network’s proverbial mouth. Propelled by an erroneous report about its content, talk of the new show bubbled up early and led to protests and boycott threats that made it front-page news from June to September, alongside Son of Sam, Reggie Jackson and Elvis.

Described simply as “the story of two sisters, Jessica Tate and Mary Campbell” (Katherine Helmond and Cathryn Damon), the serialized Soap was what newly top-rated  ABC hoped would take it from ratings champ, courtesy of cartoonish hits Happy Days and Welcome Back Kotter, to drawing-room comedy sophisticate. The laughs were mined not just from the married sisters’ large and dysfunctional families, on opposite sides of the income divide, but from the lampooning of every shopworn staple of the daytime-soap genre, short of the organ-music sting. Soap’s pilot episode featured story threads of homosexuality, gender-reassignment, patricide, racism and multiple affairs, including a mother and daughter unwittingly sharing the same tennis-pro lover. (Assignations that likely marked the first time “boff” was heard in prime time.)

If the realistic All in the Family had begun to push the envelope of prime-time convention six years earlier, the satirical Soap appeared ready to tear and toss it. But when the first two episodes were screened by affiliates in the spring, jaws dropped over its raunchy content. A June Newsweek article that referred to it as a “sex farce” and implied it featured a scene of a priest being seduced in a confessional (it didn’t) took the concern out of the boardroom and onto Main Street. Parent and religious groups organized letter-writing campaigns.

Affiliate protests and advertiser boycotts were announced. For good measure, the National…