Power in Antony and Cleopatra is ostensibly a political force, as the play turns around the competition between Antony and Caesar for dominance in Rome. But it has other facets too, most notably the effect of love as an overpowering force. Antony refuses to be dominated by Caesar, but he willingly submits his love and allegiance to Cleopatra. Power is thus a political and a personal force, one that impacts the desires of individuals in both realms.
Power is the main priority of nearly every major character in the play. Caesar is the only "honorable" character among the whole lot of them because he never pretends his actions are in the name of any thing besides his sheer desire for power.