I think the Democratic landslide in the 2006 elections has really messed the Truthers up, no doubt because it violates their fantasy.
The American people apparently don't know they've woken up. What a bunch of dummies!
There should have been a slew of Truther candidates swept into office, with Democrats and Republics alike being tossed out on their ears, 9/11 being investigated, the conspiracy guys vindicated ("You were right all along! We were stupid! Can you ever forgive us?"), the New World Order defeated, the United Nations destroyed, the tollroads defeated, a gun under every pillow, and all of humanity joined together in mutual hatred of government.
Death to the New World Order! YAY!
But it was not to be. In some vague way, the Truthers are probably brooding over this violation of their paradigm. It may have slowed them down a bit. But they'll soon forget what happened to prove they were wrong and be coming back to tell us how obvious the evidence is and how everyone really agrees with them, etc.