Life in a Bubble
The modern, tea party-inflected conservative movement is based on a few core principles. Global warming is a hoax. Income inequality hasn't been growing. Tax cuts don't increase the deficit. America has the best healthcare in the world. Evolution is a myth. The economy is weak because of regulatory uncertainty. Barack Obama is a socialist.
I'm trying to think of another successful political movement in history based on so many objectively fantastical beliefs. Not really coming up with any, though certainly there have been individual doozies here and there. Commenters?