In ORD, I dressed quite smartly (turtleneck with Versace pants and a black overcoat) that they still flagged me and wiped my hands to see if I deal with drugs....even if you dress appropriately, the TSA will still find ways to flag you if they are jealous of what you wear.

Ironically, in JFK, I was automatically sent to pre check line despite never signing up....reminded me how security is done on the other side of the Atlantic (no shoe removal and keeping belts on).....I liked it.