Well, we all generally agree that there aren't 'lizard people' in the US (we do agree that, right? ...right?), but increasingly less crazy ideas are now being regarded as similarly crazy.
Like the US president is a secret muslim from kenya in office to take away the guns in furtherance of the global warming hoax? I see aspects of that narrative on TV almost every day. It's a daily reality for millions and millions of americans.
Well they are both rather unlikely, but at least the lizard thing is testable. Poke the guy with a stick and see. Question answered. The other theories cannot be so easily disproved.
Practically speaking, you can't personally poke the guy with a stick, and you don't trust the people who claim they have poked him. That's the unresolvable problem in the debate, same as with Muslim, guns, climate, autism, etc.