The powerful ruling class has been described as "the machine", "the man", "patricians", "the establishment", and "big brother". I am looking for similar words to describe the 99%, aka the plebeians (and more specifically the proletariat).
Credit to Emma Lazarus:
"Keep, ancient lands, your storied pomp!" cries she With silent lips. "Give me your tired, your poor, Your huddled masses yearning to breathe free,
the ordinary persons, as distinguished from those who have wealth, rank, influence, etc.
"a man of the people"
A specifically derogatory term is riffraff. Especially used for the lower classes:
the lowest classes; rabble:
the riffraff of the city.
It sounds like you're looking for a political term. The best answers I can think of are stevesilva's suggestion or sheeple. Sheeple, of course, is a derogatory yet very accurate term for the masses - in some countries, at least.
Another possibility is proletariat, though it's a little more restrictive, referring primarily to the laboring class or the lower social classes.
Slang A person or group of people with less power, money, etc. than the rest of society: As a politician, her sympathy was always for the underdog in society. CDO
People of a low social position: Her speech stirred the emotions of the rabble. CDO
(Metallurgy) An iron tool or mechanical device for stirring, mixing, or skimming a molten charge in a roasting furnace CED
[C17: from French râble, from Latin rutābulum rake for a furnace, from ruere to rake, dig up]
(The) Hoi polloi: Oxford Dictionaries
The masses or common people.
The great unwashed.
great unwashed pl (plural only)
- (idiomatic) A contemptuous term for the populace, particularly the working class.
IMO, the contempt mirrors the hostility shown by phrases such as the machine.