Power based on ability to produce convictions which are beliefs and not knowledge cannot be a good thing unless it is guided by knowledge of the difference between good and evil. I shall have to teach a pupil those things as well'. The dialogue falls into three main parts, in which Socrates carries on discussion with Gorgias, Polus and Callicles respectively. Notice that Polus again wants to say how fine a thing oratory is, and Socrates insists that we must be able to say what it is before there is any point in discussing whether it is a good thing. But if you take 'will' in a restricted sense to mean 'will as an end' the argument follows.
Power means ability to achieve ends.
Re-read the passage with these meanings in mind. Now write the argument out again with 'fine' for 'A', 'pleasant' for 'B' and so on as before. This completes the second section of the dialogue. On the natural rule of the stronger see Thucydides, I.76 and V.105. On morality as protection for the weak see Thucydides, V.90 and III.84.