> Perhaps the only weapon is to teach how to think for oneself. Who is going to invest in that in a scale necessary?

_Most_ developed countries do invest in the education and teaching of critical thinking. It's not even that expensive.

In most countries, if a political party prefers an uneducated voter base, they don't win elections. Or if they do, there are enough working checks and balances (and parties in the opposition) to prevent serious harm.