While Clint Eastwood's Republican National Convention argument with an empty chair confused and amused many, some American mental health practitioners probably recognized it as a classic tool of Gestalt therapy: the Empty-Chair technique.
Gestalt therapy was invented by a German psychiatrist named Fritz Perls, an associate of Wilhelm Reich (who found fame - some would say infamy - as the inventor of "orgone therapy") and refugee who fled his native land in the wake of the Nazi Party's rise to power. In South Africa, Perls, along with his wife Laura, developed the basics of the practice: an emphasis on healing the whole self and recognizing the social environment of the patient for its impact on his or her development.
In the Empty-Chair technique, a patient is instructed to imagine a person in their lives with whom they have difficulties sitting in the chair. The patient then speaks to the seated "person", expressing his or her frustrations and fears. During this conversation he or she is encouraged to talk for the imaginary person as well, with the goal that through this process the patient will be able to recognize the projection as part of him or herself, articulating and resolving deeply-rooted emotional conflicts. It is important to note that the Empty Chair doesn't always have to be occupied by a specific individual: The therapist can direct the patient to imagine it is occupied by an object, idea or stereotype.
With this in mind, Eastwood's confrontation of the empty chair can be understood in terms of mass psychology. Eastwood, once the very image of the tough, independent white male, but who is now noticeably in decline, stands in as a surrogate for the fear of the overwhelmingly white, male Republican Party. In doing so, he addresses their fear of the youthful black President and what he represents: a change in social order that will eventually erode and overcome the established face of power--much like time has replaced the once-rugged Man with No Name with the cranky old veteran of Gran Tourino, besieged on all sides by a youthful, non-white culture on the rise.