The Smothers Brothers are Thomas ("Tom" - born February 2, 1937) and Richard ("Dick" - born November 20, 1939), American singers, musicians, and comedians. The brothers' trademark double act was performing folk songs (Tommy on acoustic guitar, Dick on string bass), which usually led to arguments between the siblings. Tommy's signature line was, "Mom always liked you best!" Tommy (the elder of the two) acted "slow", and Dick, the straight man, acted "superior".
Controversies and cancellation
With its focus having evolved toward a more youth-oriented one, the show became both popular and controversial. Three specific targets of satire -- racism, the President of the United States, and the Vietnam War-- wound up defining the show's content for the remainder of its run, eventually leading to its demise.  The brothers soon found themselves in regular conflict with CBS's network censors. At the start of the 1968/69 season, the network ordered that the Smothers deliver their shows finished and ready to air ten days before airdate so that the censors could edit the shows as necessary. In the season premiere, CBS deleted the entire segment of Belafonte singing "Lord, Don't Stop the Carnival" against a backdrop of the havoc during the 1968 Democratic National Convention, along with two lines from a satire of their main competitor, Bonanza. As the year progressed, battles over content continued, including a David Steinberg sermon about Moses and the Burning Bush.  With some local stations making their own deletions of controversial skits or comments, the continuing problems over the show came to a head after CBS broadcast a rerun on March 9, 1969. The network explained the decision by stating that because that week's episode did not arrive in time to be previewed, it would not be shown. In that program, Joan Baez paid tribute to her then-husband, David Harris, who was entering jail after refusing military service, while comedian Jackie Mason made a joke about children "playing doctor". When the show finally did air, two months later, the network allowed Baez to state that her husband was in prison, but edited out the reason.  Despite the conflict, the show was picked up for the 1969-70 season on March 14, seemingly ending the debate over its status. However, network CEO and President William S. Paley abruptly canceled the show on April 4, 1969. The reason given by CBS was the Smothers' refusal to meet the pre-air delivery dates as specified by the network in order to accommodate review by the censors. This cancellation led the Brothers to file a successful breach of contract suit against the network, although the suit failed to see the brothers or their show returned to the air. Despite this cancellation, the show went on to win the Emmy Award that year for best writing. The saga of the cancellation of the show is the subject of a 2002 documentary film, Smothered.  Highlights from seasons two and three of the show have been released on DVD, but there is no explanation of why anything from season one remains unreleased.

Q: What was the controversy about?
A: The brothers soon found themselves in regular conflict with CBS's network censors.
Why was there conflict with the censors?
racism, the President of the United States, and the Vietnam War-- wound up defining the show's content for the remainder of its run, eventually leading to its demise.
racism, the President of the United States, and the Vietnam War-- wound up defining the show's content for the remainder of its run, eventually leading to its demise.