Illiberal democracy is a new concept. I believe the term itself was coined by Viktor Orban. How does it differ from fascism?
An illiberal democracy retains the forms and protections of liberal democracy on paper, but makes them practically meaningless by corrupting or subverting them. The will of the majority is frustrated in elections by gerrymandering and government control of the media. Law enforcement and the judiciary are weaponized against the government’s critics through the appointment of blatantly partisan public officers. Freedom of speech and association are limited through regulatory harassment and the acquisition of popular media by friends of the government. Government supporters get subsidies; opponents don’t. And so on.
Illiberal democracy is a way station–but to what? Poland and Hungary need money from the EU and protection from NATO, so they push the envelope as far as they think they can go, and no further. Will the EU finally take effective action to reel them in, or will they ultimately devolve into openly fascist states? I don’t know the answer to that question, but I’m not optimistic.