Karl Lidner - Matthew Broderick

Being the only white character, Karl Lidner bring the news of the Younger Family to stay away from moving into the white neighborhood for their sake. By being a shy individual, Karl is only doing his job just for the sake of the Younger family, not for his benefit. In all means, he is not the type of person to show hatred amongst his clients, but informing them that "people want to live among their own kind". As a messenger for the white community, he is only doing what's best for the organization in the neighborhood. By offering them an incentive to stay away, the Younger refuse his offer and make it more difficult for his job.
By casting a young Matthew Broderick, he displays the true character of a what a businessman is capable of achieving throughout his career. In his eyes, he believes what is right for his future and what will definitely benefit him in the long run. His character as Karl Lidner is not in a negative persona, but more of a way of telling an individual what is right and wrong in a certain circumstance.