Try to equate the terrorist bombings on a personal level with your bleeding heart liberal friend. What if your mother was on United flight 11? What if your daughter was vaporized in the WTC, Pentagon or Pennsylvania events? Don't let them off the hook, make it AS PERSONAL as you possibly can. These folks believe in "the greater good" or "one world order" until it smacks them upside the head.
PS: Most of my family share the views of your friends and I LOVE arguing with them...good luck!
You are right. Take it down to sandbox level. They're only using their emotions, usually, anyway. ...and I LOVE arguing with them...
See? You understand me!