In my experience, most politically active people believe in some conspiracy theories. My sister believes in Contrails. My brother thinks the moon landings were a hoax. I've met tons of people who believe in some form of clandestine world government. All conspiracy theories are based more on speculation than evidence. When people are emotionally invested in something they cannot prove even to themselves, it makes them volatile.
People tend to believe what they want to believe. It's one of the reasons I taught the Bible to teenagers for 20 years. Adults tend to be more rigid in their beliefs and data to the contrary will often rile them.