There seems to be a frightening power vacuum in Atlas Shrugged. The world is collapsing and no one is doing much about it. We see a lot of examples of apathetic people who either have no power at all, or have power and choose not to use it, or don't use it effectively. From the defeated residents of places like Starnesville to the frightened and useless looters, nobody seems able or willing to act to avoid disaster. And the people who could swoop in to save the day are on strike.
Atlas Shrugged is hugely concerned with power and the lack of it, and it really redefines what power is. Power isn't just about strength and action, either physical or mental. The "looters" are all obsessed with having and using power, but it's a power based on terror and fear, and used in the service of destruction and anarchy. But Galt and his strikers have the power of resistance and of knowledge, and the power to reveal the looters for what they really are.
The looters are a bit like the man behind the curtain in The Wizard of Oz. The "great and powerful" (and loud) wizard is nothing more than a dumpy man with a fancy machine. But that dumpy man is very powerful in an insidious way. He has the power to make people believe things, to influence how they think and behave. This is the kind of power the looters have, and this is the kind of power that Galt wages his philosophical war against.
All looters have the same sort of goals in mind and seek the same type of power over people.
The looters each have very different ideas of what power is.