An interview with the President is not necessary in order to conduct the comprehensive assessment demanded by the Hare Psychopathy Checklist. The determination of a diagnosis of clinical psychopathy rests fundamentally on an analysis of the raw data of his life history, not his characterization of his life. Fortunately, there is an abundance of high quality information on Trump’s life history from informant and archival sources. The interview should not be considered the “gold standard” of psychological assessment. Indeed, there is some evidence that – with psychopaths – the interview detracts from the evaluator’s ability to make an accurate diagnosis.
  
In order to justify assigning a diagnosis to the President ‘at a distance’, we need to address a guideline in the American Psychiatric Association’s code of ethics called the Goldwater Rule. The Goldwater Rule asserts that a mental health professional has to directly examine a public figure and secure consent from them before offering up a diagnosis.

The Goldwater Rule was established because, during the 1964 Presidential campaign, FACT magazine (now defunct) invited psychiatrists to participate in a survey on the psychological makeup of candidate Senator Barry Goldwater. Psychiatrists that responded branded Goldwater with various diagnoses and descriptors, such as “paranoid,” “schizophrenic,” “psychotic,” and “narcissistic.” Most responders claimed Goldwater was “dangerous” and unfit to be President. Goldwater later successfully sued the magazine for libel. The verdict in that case and the episode as a whole was damaging to the reputation of mental health professionals.

The key rationale behind the Goldwater Rule revolved around the question as to whether you can secure sufficient, high quality information on a client without the benefit of a clinical interview. There are now various lines of research to indicate the clinical interview should not be considered the “gold standard” of diagnostic assessment and that the Goldwater Rule is antiquated. For example, research on cognitive bias shows that interviewers often display errors in judgement, such as overvaluing flamboyant or dramatic information. Interviewers are also susceptible to impression management, which refers to the interviewee’s tendency to distort their self-report in order to create a good impression. Studies reveal interviewers exaggerate their ability to detect such impression management

(9) These concerns are amplified when you might be evaluating a psychopath who is so facile with lying and never sees his destructive behavior as pathological. Indeed, in one study 

(10) with psychopaths, the diagnostician’s ability to predict future behavior was actually diminished when an interview was added to the case file data.  A recent thorough and scientific critique 

(11) of the Goldwater Rule notes there are three sources of information to draw upon In making a diagnosis: information from the client (the clinical interview); information from informants (e.g. family, friends, business associates, etc. and, if the public official is high-profile, possibly well-researched biographies); and information from archival sources (e.g. speeches, taped interviews, tweets, court records, real-time observations). A review of relevant studies indicates that information from informant and archival sources yields higher validity than information from the clinical interview.

The storehouse of high-quality informant and archival information on Trump is unparalleled. He is arguably the most well-chronicled President/celebrity/person in history. A partial list of informational sources would include:

(1) 13 autobiographical efforts (according to his Wikipedia page);

(2) 63 biographies, many of which are richly sourced;

(3) hundreds of interviews from print, radio and television;

(4) over 18,000 tweets since he announced his candidacy;

(5) social media material from his Facebook page and YouTube productions;

(6) court records (he has been the defendant in over 1500 lawsuits); and

(7) investigative reporting of shady financial dealings and alleged criminal activity.

With such an abundance of information that can be applied to a diagnosable condition where the criteria are operationalized and specific, the core pillar of the Goldwater Rule collapses.