Nixon and Trump both received coaching in machiavellianism from Roy Cohn.

Probably true. I admit that I find it difficult to understand somebody like Cohn, in the sense of having any empathy with him, or recognising his motivation as something I might share. This may be a failing, but I genuinely wonder whether some people are actually human in any real sense.

His eyes are dead in photographs.
 

I guess sociopathy is its own motivation. MrsD. and I were debating whether you could tell if someone is criminal or dangerous from a photo, media stereotypes, and ethnic factors in appearance that have been cast as movie villains, after a news story about a locally wanted serial killer suspect. I already 'knew' he was a suspect (from the story), but thought he looked pretty scary, albeit in a classic mugshot (he was smirking eerily, I thought). Mrs. said he looks like her cousins, who are/were at worst, stoners and layabouts.

This looks right up my alley, thanks.