I didn't realize that this was in Plato. As one who is wont to juxtapose Socrates with Christ, I find the passage haunting. What is so very fascinating is that Plato does not seize upon this opportunity to foreshadow, dramatically, Socrates' own very different martyrdom in the sufferings and death of the just man:
To the best of my ability and if such is the nature of the two, it becomes an easy matter, I fancy, to unfold the tale of the sort of life that awaits each. We must tell it, then; and even if my language is somewhat rude and brutal, you must not suppose, Socrates, that it is I who speak thus, but the those who will commend injustice above justice. What they will say is this: that such being his disposition, the just man whill have to endure the lash, the rack, chains, the branding-iron in his eyes, and finally, after every extremity of suffering, he will be crucified [anaschinduleuthesetai], and so will learn his lesson that not to be but to seem just is what we ought to desire.
Republic, 361e-362a (Paul Shorey, trans.).