Actually, in such a scenario the rich would be a target of the police forces of the poor. While it may not be financially beneficial to get into gun fights with your neighbor over an acre of land, and thus an agreement would need to be made. The rich would need to hire much better police forces because it is financially beneficial for the poor police forces to bind together to take land from the rich (assuming such land is the source of the riches, or even contains wealth that can be taken). The rich would be obligated to pay more for police protection.