Nearly 2 million kids are homeschooled in this country. When I was a kid there was no such thing. Then there are private and Christian schools with who knows how many kids in them. That leaves the public schools without involved parents. I know that really frustrated Christian teachers 20 years ago.
What happens after the private school students leave the classroom? They generally go to state universities or liberal dominated private universities. Then there is the generally toxic mainstream culture. The casualty rate is high, judging by church membership statistics, even recent ones from evangelicals. Unfortunately, both the major Christian groups with conservative inclinations are either compromised with liberalism, specifically the Catholic Church under the current Pope, or are focused on the Rapture as the only way out of the long term decline, as is the case with many Baptists, most independent Bible churches, and many charismatics.
Nothing is hopeless, but it will take a major tectonic shift in the economy or a sudden, precipitous loss of international power with Russia and China supplanting this country as the world's dominant powers, to loosen the death grip the political and cultural Left hold.