"If you don't agree with the war effort, that's fine. It's something we can agree to disagree on. But support for our troops is something I think we can both agree on, because those are our brothers, sisters, fathers, uncles and cousins that are putting thier lives on the line for you and I. It doesn't matter if you are a democrat or a republican; it's not about pro-war or anti-war. It's about supporting our family members who are courageous enough to be willing to die for you and I."
This argument has been successful at shutting up a number of anti-war DEMONstrators for me.