In Little Dorrit, Dickens presents England as an oligarchic political system, controlled by a small circle of elites that have managed to get themselves into permanent positions of power. Not only that, but the members of this elite are all part of the same family, participating in an unscrupulous system of nepotism and basically creating a form of dynastic rule. When combined with the totally unaccountable, slow, and generally useless bureaucracy that's at the heart of government, this novel's view of how power is wielded in England becomes completely cynical and dystopian.
Paradoxically, it's the weakest and most passive characters who end up having the most impact in the novel. No one wins through strength or action; it's mostly luck and the interference of others that bring about good things for the characters we are meant to root for and identify with.
Power is shown to be non-transferrable in the novel. Those who have it seem to have had it forever and will continue to have it forever. Those who are powerless will always remain powerless.