Answer:
It emphasizes the idea that all people should work together.
Step-by-step explanation:
Kennedy was referring to the people who were in favor of his government and those who were opposed. When he said "Let both sides," they were saying that to achieve a strong nation, everyone should work together, and that he would govern for all and not for a specific part of the population. Only through the union and work of all people could they solve the problems of the country and build a strong and unshakeable nation.