If he’s too stupid to compute that kings are not elected, let alone that we don’t have one in the USA, then he would be completely unqualified for the position, even if it did exist.
There have been lots of elected kings in history.
The Roman, Byzantine and Holy Roman Emperors were elected, at least in theory.
The Anglo-Saxon kings, the kings of Visigothic Spain, Poland and Hungary were elected at various times, as were the first caliphs and the Mongol khans.
Indeed, most European monarchies had periods when their kings were chosen at least partially by election. Absolute hereditary succession by primogeniture is actually fairly recent.
http://en.wikipedia.org/wiki/Elective_monarchy