We have decades of liberals controlling our educational system.
From grade school teachers describing "Republicans are for the rich and Democrats are for the people" to college professors leading "civil disobedience" demonstrations, the message is unceasing and liberal.
We have the Ivy League schools teaching our lawyers/judges.
All higher education is propagating leftist propaganda as they turn out progressively liberal journalists, educators, etc.
They have made higher education mandatory to land many jobs or get promotions and with that, more people are exposed to the fantasy of liberalism and the rejection of conservative values and traditions.
Of course, the entertainment industry is highly liberal and very influential.
Big Tech and Big Pharma financially support liberal movements and retain the politicians they can control and suppress criticism.
Big Tech has the ability to censor and guide searches to current events.
Don't forget foreign influence in money and power--their objective is to weaken or destroy the US.
etc.