ShrinkWrapped has an excellent analysis which I refer you to.
I say this over and over, but it bears repeating: psychological defense mechanisms (which include some relatively primitive psychological responses like projection - the mechanism involved in most forms of racism, for example) are not diagnoses. The very dysfunctional ones might be conceptualized as a process of the psychological self that is somewhat similar to when the physical self experiences a fever.
A mild fever suggests that the body is coping with an intrusion into its physical defenses. Most often the fever itself becomes self-correcting, setting off a series of defensive actions that lead to a return to normal functioning. If the fever persists and becomes too high, it becomes a red flag that something serious might be going on and the underlying cause needs to be found.
It is likewise when the ego deploys a psychological defense (especially one that persists despite reality; or one that is severely dysfunctional and causes great problems in the person's life). We do not say that "fever" is a diagnosis. It is a symptom that when it doesn't go away makes us take action. A defense mechanism is also a symptom that suggests our psychological self is trying to cope with a disturbing reality. If an individual has insight and self-awareness (the ability to objectively observe and be conscious of one's own thoughts, feelings, and behaviors and their meaning), then the defense mechanism can even becomes a valuable tool with which to understand our own fears and prejudices - just as a fever becomes the red flag that leads us to look for an underlying problem.
Quite frankly, the fact that some psychiatrists and psychologists want to make defenses themselves diagnoses concerns me greatly, since it suggests to me that there is a desire to control human behavior via pathologizing any behavior that goes against the tenets of the controlling authority.
Back in the 1980's the World Psychiatric Association condemned the former Soviet Union for doing exactly the same thing with their diagnosis of "Sluggish Schizophrenia" - which made opposition to the State's communist system a severe mental illness (see this post)
However, if I may use a sophisticated Psychiatric term to encapsulate this idea: putting this into the DSM would not only be ridiculous but it would be crazy!
The DSM (Diagnostic and Statistical Manual, which is the "official" listing of accepted Psychiatric diagnoses) already contains diagnostic entities which cover delusions (fixed, false ideas that do not conform with reality) and obsessions (preoccupations with ideas that limit a person's daily functioning). All of the examples of pathology mentioned in the article could be covered by diagnoses that contain such symptom complexes. On the other hand, once the DSM includes pathological bias, just imagine the fun the legal professional and the professional victims associations could have with such a diagnosis.
Between the Psychiatric profession's need to pathologize all forms of behavior (which tends to mitigate responsibility for selected, favored, victim classes) and the legal profession's need to make money off of any and every misfortune (which requires assigning blame for everything untoward that occurs, whether it originates from malice, misconduct, or bad luck), we are attacking some of the foundations of our society.
Instapundit sums it up nicely:
So when homosexuality was unpopular, it was a mental disorder. Now that it's popular, not liking it is a mental disorder. Evidence for either position? Not much. My diagnosis: How about we recognize a disorder consisting of turning intellectual fashions into pseudoscience? Seems like this is a case of "mental health" consisting largely of agreeing with whatever political opinions psychiatrists hold at a particular moment in time. Psychiatry, heal thyself.
Can "Republicanism" be far behind as a new diagnosis in DSM-V representing extreme bias? I expect not, if some have their way.
UPDATE: Sigh....Like I said.... It is instructive, I think, to note which side of the political spectrum eagerly anticipates this sort of perverted social engineering and control; and which side finds it oppressive and an assault on human freedom.