Dr. King refers to peaceful protest when referencing the "majestic heights". He describes peaceful protest as meeting physical force with soul force, or the will to see that justice is enacted through nonviolent means. This is truly a difficult thing to accomplish in the face of brutal injustice, and is a majestic height to reach indeed. Dr. King proved that such heights could be reached, and that real progress toward equality could be made by nonviolent means.
The irony is that they are smiling with “torn and bleeding hearts”.
The idea it emphasizes is that they are smiling to hide their pain.
The overall message revealed by the irony is that they are in considerable emotional turmoil and faking happiness to mask their distress.
Answer:
They help readers know when to pause or slow down their reading.
