Appearances by Ronald Reagan in the 1970s on television according to the IMDB which could be consideted less than serious.
1970 The Carol Burnett Show.
1972 The Sonny and Cher Comedy Hour
1973, 1974, 1977 The Dean Martin Celebrity Roasts. In 1973 Reagan was the one roasted.
But I only heard Dems deride him for Bedtime for Bonzo and (more rarely) Death Valley Days: never for the appearances you cited.
Cheers!