The first three articles of the U.S. Constitution establish a separation of ruling power among the executive, legislative and judicial branches, one of several principles common to democratic industrialised nations. Though some have complained about the principle's lack of efficiency, others argue that this counts among its benefits.
Political scientists frequently cite the prevention of tyranny as the reason the separation of powers was written into the American Constitution. James Madison, in the 47th Federalist Paper, said such a "dangerous tendency" for power to accumulate would be argument enough for citizens to abandon the system and revolt. The separation itself is just the start of several provisions that have attempted to balance the influence of the three branches.
Checks and Balances
The separation of powers led to numerous checks and balances to further limit the accumulation of power by any particular sphere of government that holds sway over ordinary citizens. For instance, the presidential veto is often employed by the executive branch to block laws passed by the legislative branch; however, that veto can be overridden by a two-thirds vote of the Congress.
Numerous oversight responsibilities are granted to the legislative branch, which gives legislators access to many federal or judicial records, as well as the power to sanction activities they deem unjust in a public forum. In another form of balanced oversight, the federal and local court systems often decide the constitutionality or legality of the various laws and executive policies that are passed and carried out across the country. The separated structure of government also allows for each branch to have oversight into different functions of people's lives, providing a level of bureaucratic organisation and specialisation.
Fairness and Accountability
Though some claim the separation of powers makes policy change more difficult by adding layers of bureaucracy, many agree that fairness and efficiency is at the forefront. The "rule of law" theory of government, first explored by Roman and Greek philosophers, maintains that the people who make laws shouldn't be the same people who enforce and punish the breakers of those laws. Accountability is enhanced in this way, as well.