re: Lashing out
"We don't see this kind of response from the families of the Pentagon victims, or from the families of those killed on Flight 93. What's different about these groups? "
The families of Pentagon and Flight 93 would be dispersed around country. Those in Trade Center would have tendency to one locale, plus they are more victims. This would result in the Trade Center victims having more political power. Oh, also NY was the location which was the focus for people to visit to witness event- so this adds further political power.