Public high schools back in the day. Along with the books on Federalism, all of that. The conservatives knew the way to change the narrative was to go after the public school circulum, the textbooks, etc. After that didn't work fast enough, they went with the culture wars Sumner was part of and found more sexy and religious topics to get people to pull their kids out of school.
Now they're privatizing the schools and teaching corporate values, eliminating the history of the US and the world, all to fit their world view. I just call their movement fascism, using the means that Mussolini and Roosevelt would both agree would define it. We're on a hard road here, and most people don't have the money, time or leisure to engage on this level. Those who can make use of the knowledge can spread their own conclusions about it to them.
Our venues of communicating these ideas, because of the destruction of the commons and the selling off of the media (as well as the post office, which was once enshrined as place to disseminate important political ideas) is well on the way. I feel discouraged when I see things reduced to the internet only, because that is under corporate control and the knowledge can be cut off or erased. At the owner's whim.
We have to consider this in line with the repression of expressing oneself in public like OWS is attacked, that we are going to have a hard time with mass organizing. The media has got most people thinking that the mass movements of the past should stay in the past, that it's somehow unseemly to protest, and a threat to them. Also with all the hate dog whistles from Sumner, etc.
I could be wrong, but that is the trend to me. And if you'd like to have more discussions of this nature, there's always the Socialist Progressive group here. If you're not already subscribed. Or some of the others.