what is brutus's purpose in addressing the plebeians?

Brutus tells the masses that he loved Caesar more than any of them, but that he killed Caesar because he loved Rome more. He wants them to understand why he took part in the murder. He says, "As Caesar loved me, I weep for him. As he was fortunate, I rejoice at it. As he was valiant, I honor him. But as he was ambitious, I slew him" (3.2.23-25). Brutus then asks them if they wish him to die for his actions, to which the crowd replies, "Live, Brutus, live, live!" (3.2.44).