Yes, you have a valid argument. The Goldwater rule is the informal name given to section*7 in the American Psychiatric Association's (APA) Principles of Medical Ethics.
However, the American Psychoanalytic Association (APsaA), a different organization from the APA, sent a letter on June 6, 2017, that highlighted differences between the APA and APsaA ethical guidelines, stating that "The American Psychiatric Association's ethical stance on the Goldwater Rule applies to its members only. APsaA does not consider political commentary by its individual members an ethical matter."
There is also an ethical duty to warn the public:
John Gartner, a practicing psychologist, and the leader of the group Duty to Warn, stated in April 2017 that: "We have an ethical responsibility to warn the public about Donald Trump's dangerous mental illness."
Donald Trump has 'dangerous mental illness', say psychiatry experts at Yale conference | The Independent