The PC / Progressive Left Strategy: Strive To Win The Debate Before It Starts By Shutting Down Criticism

The standard liberal/conservative method for winning acceptance of policies and social changes involves honing arguments and swaying opinion via public reasoning. The PC / progressive left seeks to win by shutting down opposing views. You could say: they don't seek to win the debate: they seek to shut it down. Or you could say: they seek to win it before it really starts, by shutting it down. 

   This is a smart--though evil--tactic. 

   It's particularly suited to a radical movement because (a) as its positions become more and more radical and insane, they become more and more difficult to defend in open debate, and (b) as their supporters become more and more radical, they become more and more willing to shout down, threaten and physically assault the opposition.

   So...from a purely tactical perspective, you've kinda gotta hand it to 'em.