Donald Trump is very skilled at lying - much more so than most politicians. One reason for this - is he's somehow managed to dramatically reduce his frequency of self-touching. Most (but certainly not all) body language displays involving touching another part of one's own body (most notably, but not exclusively - the face) indicates a significantly heightened level of anxiety. Another possible explanation for this is that Mr. Trump feels less anxiety when he lies (compared to the average person).
Jimmy Kimmel last night regarding the possibility of a debate with Bernie Sanders, Mr. Trump held onto his left wrist for an extended time. With any human being in such a setting - this nonverbal display would signal a heightened level of anxiety - and for Trump it is significantly more so. Review every single minute of his interviews, debates, appearances, etc., since June 2015 when he announced his candidacy - I challenge you to find a similar body language display by Mr. Trump.
Trump responds, "I've never really had the privilege."
And then he displays this "Bitter-Anger expression - which sometimes is referred to a "Bitter-Smile" because the person making it, believes (in real time) that they're eking out a bit of a smile. This is an excellent example of just how inaccurate we all are between the expressions we THINK we make - compared to those which we ACTUALLY make - when we're far from our emotional baseline. It's a fundamental axiom of nonverbal communication.
In summary, although Trump SAYS he would rather face Bernie Sanders in the general election, he DOES NOT BELIEVE THIS at all. Trump is lying.
This website serves as an objective reference source for the science and art of Body Language/Nonverbal Communication. In an effort to be both practical and academic, many examples from/of varied cultures, politicians, professional athletes, legal cases, public figures, etc., are cited in order to teach and illustrate both the interpretation of others’ body language as well as the projection of one’s own nonverbal skills in many different contexts – not to advance any political, religious or other agenda.
Nonverbal Communication Analysis No. 3247: Barack Obama's Response to Question regarding Revoking Bill Cosby's Presidential Medal of Freedom
Nonverbal Communication Analysis No. 3570: Donald Trump's Duplicitous Thumb
Nonverbal Communication Analysis No. 3568: Hillary Clinton, (Low) Likability, Rapport (Destroying) and Body Language
Nonverbal Communication Analysis No. 2701: Cuddling, Romance, Affection and Foot-Shunning
Nonverbal Communication Analysis No. 3535: Prince, Sexual Signals and Body Language