Heinlein always seems to have realized that, in a world with limited elbow room and the ability to fail very hard, government is both inescapable and actually valuable--and beyond the "blind arbiter of contracts" that you hear out of the libertarian bucket. I liked how Spider Robinson put it (although the article it comes from[1] is kind of fawning):
a man who bitterly opposes military conscription, supports consensual sexual freedom and women's ownership of their bellies, delights in unconventional marriage customs, champions massive expenditures for scientific research, suggests radical experiments in government; and; has written with apparent approval of anarchists, communists, socialists, technocrats, limited-franchise-republicans, emperors and empresses, capitalists, dictators, thieves, whores, charlatans and even career civil servants.
I'm not a libertarian (because I don't believe the strong should rule the weak, and I don't think Heinlein does either) and it's hard to find anything that in principle I can't be cool with.
[1] - http://www.heinleinsociety.org/rah/works/articles/rahrahrah....
And, yeah, they were very influential on me as well, and the experiences of life also prompted me to adjust some of those beliefs. But that's a pretty normal thing, I think.
Even going back to his first juvenile in 1947, Rocket Ship Galileo, the scientist protagonist is very surprised at how well educated in science, math and engineering are the group of high school students he falls in with.
And he wrote rather a lot on this elsewhere, e.g. comparing what he, his father and his grandfather were taught. The rot has been going on for a long time. One book traces it back to the Unitarians capturing Harvard from the Congregationalists in the 1810-20 period, I use the 1930 when phonics were successfully attacked. That we're still arguing that, 50 years after the publication of Why Johnny Can't Read, tells us just about all we need to know about the US educational establishment.