I remember when Howard Dean couldn't correctly state the total number of people in the Army and it was like the end of the world.In most other countries, this would be true. But the main project of the American right (including much of the Democratic Party!) has been to get the American public and media to believe totally false things. This has been going on for decades.
But the top House Republican (like the president and vice president of the united states and most other Republican Party elected officials) can't correctly state the relationship between tax rates and federal revenues, which seems like a big deal.
--"There's no connection between industry and global warming."
--"We're defending democracy in the Middle East."
--"When you raise taxes, revenues go down."
Lather, rinse, repeat. You get the public to accept demonstably false things, and you run with it. Eventually, they'll be convinced of anything, like say that Iran poses an existential threat to the country.