Article I, Section 2 of the Constitution sets three qualifications for representatives. Each representative must (1) be at least twenty-five years old, (2) have been a citizen of the United States for the past seven years, and (3) be (at the time of the election) an inhabitant of the state they represent.
In this excerpt, the word tension means discomfort. Dr. King is saying that a certain level of discomfort is necessary for growth as a country. The group(s) that have been oppressing the black community are to expect nothing short of discomfort. Facing difficult emotions is the only way that we, as a community, can make any sort of change.
During American involvement in WWII, propaganda was used to support the war cause. I hope I could help. Have a wonderful rest of the day.
