The I Have a Dream speech gives us the standard story of America. According to this story, America starts with the Declaration of Independence, which states our foundational values, particularly equality. The Founders’ Constitution turns these values into law—imperfectly at first, but American history is a progress towards redeeming the “promissory note” of the Declaration, and one day we will “live out the true meaning of … ‘all men are created equal.’”
This story is comforting and reassuring, but it is actually a barrier to progress, as the King of The Other America came to see. For one thing, it supports what he called the indifference of the good people, the idea that social progress “rolls in on the wheels of inevitability.” For another, it tells us to look to Founding America and the Declaration of Independence as the source of our fundamental ideals. But doing that tells us that those ideals can co-exist with white supremacy. The truth is that Founding America was not a nation dedicated to our idea of equality. The Betsy Ross flag shows us thirteen stars in a circle, and every star represents a state where slavery was legal.
The idea that the Declaration provides the way forward is deeply problematic.

… all the men in all the lands may live out their lives in freedom from fear and want.