Meme warfare, tax evasion, and a couple well timed "incidents" would do it.

The state is already being defeated through the propagation of anti-american ideas. It's just not being done by us and it's making the country worse instead of better. But reproducable ideas are always what ultimately powers change. 

They don't even have to be true - we just need to out propaganda the current propagandists. And we are doing a good job so far.