The families of Pentagon and Flight 93 would be dispersed around country.

Flight 93, yes. In fact, all of the families of airline passengers.

The Pentagon, I don't think so. People, once assigned to DC, tend to get a house there. If reassigned, they sell the house. Would the family move away if one of its members died? Have the people in NYC?

Even though veterans' benefits are not what they ought to be, I believe the military takes care of people during the bereavement process, because bereavement is such a vivid possibility for the families of those in military service. Familiarity and necessity have made this so. Those families have better support. They don't need to seek validation through the haphazard processes that other families have embraced.

Flight 93 is a special case. They were victims, yes, but they also, as a group, wrested control away from their attackers. There's not that same tendency for their families to be angry at people who didn't take care of them because they took care of themselves.

Those in Trade Center would have tendency to one locale, plus they are more victims.

Agreed.

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.

The WTC families have more voices, but I believe they are using their voices this way precisely because they feel powerless and forgotten. They have no political power except what noise they can make, and they have no significant social support either. They are supposed to be valiant and trot out for patriotic occasions, and otherwise be quiet. Some of them are not responding well to this, and are giving an unfocused and unfair expression to their anger. They need something else, but in its absence, they will take what they can get.