General Discussion

Per one body language expert, Trump was engaging in 'Duping Delight'.
https://www.rawstory.com/trump-admission-body-language-debate/

He knows he is lying but delights in lying.

Another article is a Psychopathy Checklist.
Some of these were evident by Trump during the debate; some were referred to indirectly.

https://en.wikipedia.org/wiki/Psychopathy_Checklist

Item 1: Glibness/superficial charm
Item 2: Grandiose sense of self-worth
Item 3: Need for stimulation/proneness to boredom
Item 4: Pathological lying
Item 5: Conning/manipulative
Item 6: Lack of remorse or guilt
Item 7: Shallow affect
Item 8: Callous/lack of empathy
Item 9: Parasitic lifestyle
Item 10: Poor behavioral controls
Item 11: Promiscuous sexual behavior
Item 12: Early behavior problems
Item 13: Lack of realistic, long-term goals
Item 14: Impulsivity
Item 15: Irresponsibility
Item 16: Failure to accept responsibility for own actions
Item 17: Many short-term marital relationships
Item 18: Juvenile delinquency
Item 19: Revocation of conditional release
Item 20: Criminal versatility