Power is for those who have the skill to seize it in a free competition.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“Northern writers, even so late as Locke, argue as to what happened in the Garden of Eden, and think that they can thence derive proofs that certain kinds of power are “legitimate.” In Machiavelli there is no such conception. Power is for those who have the skill to seize it in a free competition. His preference for popular government is not derived from any idea of “rights,” but from the observation that popular governments are less cruel, unscrupulous, and inconstant than tyrannies. Let us try to make a synthesis” source