In the 1960 Presidential elections, John F Kennedy became the democratic candidate despite his Catholicism.
This was surprising since Anti-Catholic sentiment was pretty high in mainstream American society at the time.
This was also seen as a reason why his presidential win was the closest in the history of the United States with a margin of just 118,000 out of 69 million votes.
Firing the joint chiefs of staff would look bad for Kennedy because it would make it appear to the public that the administration is struggling/weak. Anytime there are scandals or issues in which the president does not get along with his colleagues, it is seen as a sign of weakness. During Kennedy's presidency, the last thing the United States government wanted was to appear weak. This is because the US was in constant competition with the Soviet Union for international power and influence.
B. Never reach your full potential
The purpose of treaties between the U.S. Government and Indians was to first of all keep peace between the two and give colonists permission to settle Indian land. Hope this helps!