I'm not sure where GP is going with this, but for example the Habsburger lower lip [1] is a easily identifiable feature from inbreeding in Western European nobles. If you can identify it it gives you a good clue about the socioeconomic class of the person, which gives you a good clue about their political orientation.
I'm sure many more subtle examples also exist.
1: https://de.wikipedia.org/wiki/Habsburger_Unterlippe