While being a genius in the fields of language, philosophy, and political theory, Marcus Tullius Cicero is remembered as a champion of republican values, of natural law, defender of liberty and justice etc. In fact, Cicero is one monumental hypocritical bastard!
For all his stances on justice & liberty, he never once criticized the institution of slavery. He never spoke in favor of class or land reform.
He was always mercurial in his politics, always bending in the wind and changing his bets in order to maintain appearances of moderation. He was never a moderate in truth, but a supporter of the Optimates; a hater of democracy and defender of the oligarchy!
Since he claimed that government MUST protect private property, and since he never attacked slavery, (slaves being private property) that made him a supporter (nay, a champion) of slavery! In the so-called Catilinarian conspiracy, Cicero's stance is anti-labor & in favor of the rentier class. Cicero was opposed to the cancellation of debts (something which we ourselves require in the present).
In one of his letters, Cicero admits how he wished he had been invited by those 'liberatores' to kill the tyrant in the senate house.
While a man of intellectual brilliance, Cicero's character was absolutely grotesque & hypocritical - he was a fearsome enemy of the common people.