The Smothers Brothers show continued its anti-war satire against Nixon. The new president wasn't amused. It was later revealed that some Nixon campaign funds were used to pay for a private investigation of the Smothers brothers.
Tensions continued between the brothers and CBS censors. Then in April of 1969 - just three months after Nixon had taken office - the network canceled the show. Its excuse was that Tom Smothers had failed to deliver an advance tape of a sensitive segment in a timely fashion. Smothers later claimed the network had killed off the show under pressure from the Nixon administration.
The Trump tweets are in sharp contrast to that letter Lyndon Johnson sent to the Smothers Brothers in 1968. It read: "It is part of the price of leadership of this great and free nation to be the target of clever satirists. You have given the gift of laughter to our people. May we never grow so somber or self-important that we fail to appreciate the humor in our lives."