Seth Godin (@ThisIsSethsBlog) has shown the power and influence of Tribes. Much can be achieved by a motivated group of focused people. As Seth shares, groups as small as 1000 can have far-reaching effect.
In the political arena, this dynamic is often only partially effective.
Much the same way that a dog encounters a real problem when it actually catches the car, a "successful" political Tribe often encounters difficulty post victory.