Take your children out of government schools. Either homeschool or send to private schools of your choosing.
I've already got my son in a private Christian school... But along with that, he (at age six) understands that there are people out that that will be more than happy to take our freedoms away.
He knows that the correct answer to "any guns?" is "No. My mom and dad said those things are too dangerous." He knows not to talk about politics to anyone without checking with me first to see if it's okay to do so. I've also told him to answer with vague stuff political about Star Wars and Jedi Masters if someone pressures him, and then to come and tell me who was doing the pressuring.
Then, at night, when the little guy goes to bed, he says his prayers thanking God for his "family, mommy's delicious meals, daddy's guns, all my toys, and especially Your son Jesus, that died on the cross for our sins".
He becomes more politically aware every day, and knows that evil exists... My job is to make sure he knows how to handle it before he actually has to.
I do wish that were possible for all children.