The party could create rules allowing them to kick him out. There's nothing preventing them from doing so. The government cannot prevent them from doing so because of the free association bit in the constitution. So while they might denounce him, they're not actually doing anything about it. Frankly though, I don't think they need to. The guy has no chance. The state party denouncing him should be enough, especially with the problems creating provisions to expel members from the party could create.