While on the topic of telling the truth in politics, take a look at Farhad Manjoo’s recent book True Enough: Learning to Live in a Post-Fact Society. It’s a thoughtful exploration of the impact new media technology has on our sense of what counts as "true." He points to things like Wikipedia and political smear campaigns that thrive on the web as examples of how society’s notion "fact" might be changing–becoming a bit more mutable–as the information age evolves.

But he can probably explain it better himself. Here’s a video of him laying out his argument, followed by some comments and rebuttals from other presenters: