Answer:
When writing a restrictive clause, introduce it with the word "that" and no comma. However, if the subject is or was a human being, use "who" to introduce the clause. When talking about people in defining (restrictive) relative clauses, who is preferred to that.
Debacle means <span>a sudden and ignominious failure; a fiasco.</span>
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.
