Answer:
non-government agencies
Step-by-step explanation:
Non-government agencies refers to a group that act independently from the government, but still operated to influence United States' politic. Rather than directly involved in the legislation, non-government agencies influence politic through public support.
By increasing awareness to a certain issue, non-government agencies could make potential voters cast their vote toward a certain candidate which supported by the agencies. That candidate will pass the legislations that the agencies want by the time he/she elected into office.
Example of non-government agencies are Greenpeace, International Rescue Committee, Amnesty International, etc.