The … President of the United States cannot stand above the battle engaging in vague little sermons on brotherhood. The immense moral authority of the White House must be used to offer leadership and inspiration to those of every race and section who recognize their responsibilities. And the immense legal authority of the White House must be used to direct implementation of all Constitutional rights, protection of the right to vote, fulfillment of the requirement of school desegregation, and an end to discrimination in the government's own midst—in public contracts, in employment and in all Federal housing. —John F. Kennedy, speech to the National Association for the Advancement of Colored People (NAACP), 1960

Which kind of special interest leverage did the NAACP have in this situation to persuade Kennedy to support them?

Sway over voters
Corporate endorsement
Power over the judiciary
Backing of congressional representatives