Elites who, despite their power, wealth, or influence, are prone to making serious errors when discussing science and other technical matters. They resort to magical thinking and scapegoating with alarming ease and can usually be found furiously adding fuel to moral panics and information cascades.
For a given elite to be considered part of the ignorati, he must regularly provide opinions or report on matters he does not understand and has clearly made no attempt to understand. Due to the nature of their professions, journalists and politicians are usually ignorati.
"...blame evasion was getting out of hand. Newspapers were saying that sudden acceleration was caused by malfunctioning cruise-control mechanisms. The Center for Automotive Safety was claiming that radio waves made the computers on cars act up. Other ignorati pointed fingers at arcane goings-on within transmission housings and fuel-injection systems..."
-P.J. O'Rourke, Parliament of Whores