We often think of Cicero (when we do at all) as a sort of caricature, a central-casting speechifying old dude in a toga. And yeah, he was an unequalled orator, the measuring stick against which future generations of speakers would compare their efforts. He was perhaps the best writer in the constellation of great writers produced by imperial Rome, a colossus of Latin language. It was his work, rediscovered in the 14th century by Petrarch, that triggered the Renaissance and inspired the greatest Enlightenment thinkers. No small legacy.
Even with that resume, Cicero's greatest contributions might have been as the voice that spoke on behalf of republican principles as Rome plunged into dictatorship under Julius Caesar and Mark Antony. He literally gave his life in defense of the concept of political power held by the people rather than a despot.
We could use a Cicero today - classically educated, committed to popular government, willing to stand against creeping plutocracy, and able to articulate our shared values.
Anyone?