In the late 50s and early 60s people who migrated from the Dust Bowl states in the South and Midwest to Bakersfield did, among other things, created a subgenre of raw country music called the Bakersfield sound. It was far less slick and more real than established country music at the time (such a familiar refrain). Buck Owens and Merle Haggard are the most famous adherents to this musical style but it has influenced everyone from Creedence Clearwater Revival to Dwight Yoakam, still being a powerful force in music today.
And I'd say this, for at least Merle Haggard, like some of the guys who are also part of outlaw country, are much more critical of the political status quo than most country artists. He certainly is not as liberal as Willie Nelson or Roseann Cash but struck a distinctly anti-war tone on his music during the Bush administration (though I don't agree with all of his political choices). If nothing else, he espouses the ideas around being independent and critical of authority. I think the artists influenced by him and his music tend to be on the outskirts of the Nashville mainstream, being less slick and not as tied to the country music machine. So, enjoy the documents above and an important piece of music history.