The separation of powers has its historical origins in the state theories of John Locke and Charles-Louis de Secondat Baron de Montesquieu in the 17th and 18th century. They developed, what today is called horizontal separation of powers.
Due to the separation of powers the power of the state is limited. In addition to the original horizontal separation of powers there are now more forms of the separation of powers.
Classic division of state power on three powers: legislative, executive and jurisdiction
Division of state power to the Federal Republic of Germany and the individual Laender (countries).
Division of decision-making power to several groups (for example, government, parliament, interest groups). Thus, each of the participating groups is controlled and limited.
Thus, in the context of elections, the individual mandate holder gets the office only for a limited time, a time-sharing and limitation of power is established.
All citizens, not just the elite members of a group will have access to the government offices.
The Constitution restricts the ability of office-holders in the state. It gives a frame which can be modified only in a limited way.