The most sensible discussion I've seen on this topic today (from popehat.com):
1. Nazis are scum.
2. Principles are in a constant struggle with viscera. I want punching Nazis to be acceptable, and find the spectacle of Nazis getting punched to be viscerally satisfying. Jesus Christ and John Donne aside, Nazi suffering does not move me. But I know that sucker-punching someone because their views are evil is wrong.
...
1. Nazis are scum.
2. Principles are in a constant struggle with viscera. I want punching Nazis to be acceptable, and find the spectacle of Nazis getting punched to be viscerally satisfying. Jesus Christ and John Donne aside, Nazi suffering does not move me. But I know that sucker-punching someone because their views are evil is wrong.
...
On Punching Nazis
