Why did JFK not have a mandate for his proposal

Answer: Because a conservative coalition of Republicans and Southern Democrats blocked many of Kennedy's measures

Explanation: John Fitzgerald Kennedy often referred to by his initials JFK, was an American politician who served as the 35th president of the United States from January 1961 until his assassination in November 1963. He served at the height of the Cold War, and the majority of his work as president concerned relations with the Soviet Union and Cuba.

In terms of domestic legislation however, Kennedy's record was less successful, as Congress repeatedly blocked his policy proposals. Some of the reform proposals Kennedy made that were rejected by a conservative Congress include,

medical care for the aged; rebuilding of blighted urban areas as well as federal aid for education.