The problem is getting folks to buy into the defense against tyranny. They don't see it - which drives me nutty at times.
They cannot see the USA going towards a tyrannical direction.
They misread history and psychology.
Countries fall apart after crises and become tyrannical. The case of Germany after WWI is case in point (not playing the Godwin card) but just a collapse of civilization. Americans can act like monsters.
The oppression of blacks (and gun control laws aimed at them), Japanese camps in WWII, atrocities like My Lai, Abu Ghraib and the shooting of students at Kent State (all controversial, I know) show how standard citizens can become tools of the government. The Miligram and Zimbardo experiments show how simple manipulations make the average citizen become an instrument of oppression.