When he was set free, Lucius was neither accepted by the dark nor the light sections. The dark section, where many death eaters had bribed their way out, had seen him as a traitor after he had sold some of them out and banged them up in Azkaban, whereas the light side didn’t like him that he got away for his actions and believed that he had bribed his way out. So, he moved his seats to the neutral section, where he was accepted. The dark lost a lot of power, because of the moving of seats, whereas the neutral section was nearly as powerful as the light section, but they were missing some votes.