Starting with this plague of locust, we find a noticeable stress on the comings and goings of Moshe, beyond merely as a necessary detail to explain where he is. It seems as though the coming before Pharaoh, and the leaving his presence, is an independent focus of the story, without reference to what happens or is spoken during the encounter.
The nature of the parasha break of Bo is clear - starting with this plague of locust, God is telling Moshe that the confrontation with Pharaoh is to be a personal one - he is to go to face Pharaoh directly and engage in a test of wills with him. The verbal content of Moshe's speeches is now secondary in importance to the actual personal appearance that he must make. Moshe is to overcome Pharaoh on the personal level. Why is this necessary?
God sends Moshe to battle Pharaoh so that Moshe should experience first-hand the clash of titans, the battle of God's word against the vainglory of human power, of emperors and tyrants. This is qualitatively different than merely observing the battle from the side-lines, as the Egyptians and the Jews were doing. God wants Moshe's personal involvement, and he switches Moshe's role from the representative of the Jewish people, speaking in God's name, to the representative of God Himself.
This is the moment when Moshe becomes more than a leader. This is when he begins to become "ish ha-elokim," who will bring the Torah down from the mountain.
