Now the time has come for this nation to fulfill its promise. john f. kennedy said this quote in his speech. how can this quote relate to "i've been to the mountaintop" martin luther king?

Kennedy said this in a speech about furthering civil rights goals in the UN, which of course is what Martin Luther King had done. Both were calling for the US to hold true to its promise to form a more perfect union. 

Iwould but i can’t