Jacob Levy has an excellent post on why respect for truth is a foundation for republican government:
…the great analysts of truth and speech under totalitarianism—GeorgeOrwell, Hannah Arendt, VaclavHavel—can help us recognize this kind of lie for what it is. Sometimes—often—a leader with authoritarian tendencies will lie in order to make others repeat his lie both as a way to demonstrate and strengthen his power over them.
Saying something obviously untrue, and making your subordinates repeat it with a straight face in their own voice, is a particularly startling display of power over them. It’s something that was endemic to totalitarianism. Arendt analyzed the huge lies and blatant reversals of language associated with the Holocaust. Havel documented the pervasive little lies, lies that everyone knew to be lies, of late Communism. And Orwell gave us the vivid “2+2=5.”
Being made to repeat an obvious lie makes it clear that you’re powerless; it also makes you complicit. You’re morally compromised. Your ability to stand on your own moral two feet and resist or denounce is lost. Part of this is a general tool for making people part of immoral groups.
…insisting on the difference between truth and lies is itself a part of the defense of freedom. Orwell, Arendt, and Havel teach us that the power to tell public lies and to have them repeated is evidence of, and a tool for the expansion of, a power that free people should resist and refuse.
I would put it this way: Respect for the truth is tied to individualism because any person may have truth and reason on their side. But the acceptance of the public lie signals that only the will of the collective matters.