How does Douglass's opening reference to the Declaration of Independence reinforce his message

It is significant because a prominent leader was suggesting that the unequal treatment of African Americans was in direct opposition to the principles of the Declaration of Independence.

Answer: The correct answer is : The message is reinforced by Douglas giving him a lot of authority and also reinforcing the idea of the great principles of political freedom and natural justice. During his speech he shows that he is polite. He wanted to present a simple speech, with a positive message for people and that no one was affected. Douglas gives a sad regret in his speech to the issue of slaves. He said verbatim: the Declaration of Independence is the ring to the chain of destiny of your nation; So, in fact, I consider it. The principles contained in that instrument are saving principles. Respect those principles, be faithful to them on all occasions, in all places, against all enemies and at any price.