Then there IS the truly delusional and irrational. Trump Derangement Syndrome is akin to mental disorders cataloged in the DSM-V. Perhaps one could call it a collective borderline personality disorder, in which mass cognitive processes are distorted by dissonance, and reason is subsumed by paranoia. Rage and dysphoria are the earmarks of this disorder.
The echo chamber of the MSM stimulates and encourages this collective anxiety.