> You don't just need to establish that students should learn history, literature, etc -- you need to establish that 12 years of that is not enough, and they need to take an additional 4 years at a much higher cost.

Actually, I didn't get 12 years of most of the liberal arts courses I took at university. A number of them were completely new to me - no exposure in K-12 at all.

And you're being creative with numbers. No - for an engineering degree, you don't need to take 4 more years of humanities courses. Just a few credits that extend your education by (likely) less than a year.