How can we limit the lying promoters of modern liberalism and cultural Marxism?

People will always lie, but President Trump is right to call out the fake or lying news. But lying goes way back to ancient differences between castes; warriors were taught not to lie, but merchants not so much, because lying about how much ammunition remained could kill a lot of men, whereas lying about the price of products could merely cheat people.

As warrior societies retreated and merchant societies expanded so did the lies. So we now have the lying Big Media, movies, television, newspapers and of course the lying internet. But deeper than that we have academics who have legitimized lying; post-moderns like Derrida, Foucault, Lyotard, and their lesser American followers, have created what amounts to an elaborate defense of lies by claiming the relativity of truth where only power can decide the difference.

So what can we do about it? Go back to warrior societies? Punish the merchants? Break up the Big Media liars? March through the academies? We have jammed different ethnic/racial groups together in the same living space due to, you guessed it, the lies of multiculturalism, yet still we have people who are naturally or genetically more beholden to their own kin and ethnic group than other groups, so natural competition between groups multiplies the lying.

Developing ethnostates and ethnopluralism within our constitutional separation of powers and states would limit the lies and help solve many of the modern problems we have, such as our increasing alienation, or the civil strife leading to civil war, etc, which the lying promoters of modern liberalism and cultural Marxism have caused.