"when the conservative is peddling demonstrably false information like "vaccines cause autism" or "climate change is a hoax"."
How do you know this is not the case?
If you were around in Galileo's time you would be one of the ones calling him to be burned at the stake for saying Earth is not at the centre of the solar system.
More recently, Robin Warren was ridiculed for saying stomach ulcers were caused by bacteria and not caused by stress, as everyone believed.
And what did the experts tell us about the cane toads? Now looks what's happened because we believed them!!!
