It's very interesting that one of the most contentious and controversial parts of the speech - often quoted - that in 15 or 20 years' time the black man will have the whip hand over the white man is actually Powell quoting one of his constituents. I didn't know that, and, I suspect, a lot of other people will not know that either. Here is that section of the speech:
A week or two ago I fell into conversation with a constituent, a middle-aged, quite ordinary working man employed in one of our nationalised industries.
After a sentence or two about the weather, he suddenly said: "If I had the money to go, I wouldn't stay in this country." I made some deprecatory reply to the effect that even this government wouldn't last for ever; but he took no notice, and continued: "I have three children, all of them been through grammar school and two of them married now, with family. I shan't be satisfied till I have seen them all settled overseas. In this country in 15 or 20 years' time the black man will have the whip hand over the white man."