I just read a very excellent article that talks about truth and why is politically important. It's called Who Cares About the Truth?

Here's a choice exerpt:

"It follows that a necessary condition for fundamental rights is a distinction between what the government -- in the wide sense of the term -- says is so and what is true. That is, in order for me to understand that I have fundamental rights, it must be possible for me to have the following thought: that even though everyone else in my community thinks that, for example, same-sex marriages should be outlawed, people of the same sex still have a right to be married. But I couldn't have that thought unless I was able to entertain the idea that believing doesn't make things so, that there is something that my thoughts can respond to other than the views of my fellow citizens, powerful or not. The very concept of a fundamental right presupposes the concept of truth. Take-home lesson: If you care about your rights, you had better care about truth."

And another one:

"governmental transparency and freedom of information are the first defenses against tyranny. The less a government feels the need to be truthful, the more prone it is to try and get away with doing what wouldn't be approved by its citizens in the light of day, whether that means breaking into the Watergate Hotel, bombing Cambodia, or authorizing the use of torture on prisoners. Even when they don't affect us directly, secret actions like those indirectly damage the integrity of our democracy. What you don't know can hurt you."