It is when that extremism leads to the utter destruction of liberty.
Excuse me, but the Left is doing a damn fine job destroying liberty, not the Right. If we fight, we fight for our God-Given Liberty, and for the Constitution. They have both Houses of Congress, the Presidency, the Media AND the Bureaucracy. At a certain point, we are left with very few options. They want us to fight back, to have an excuse to take away the freedom of We The People.