Answer:
Any of the following could apply to the scenario detailed in your question:
- Federation
- Liberal Democracy
- Presidential System
- Federal Republic
- Constitutional Republic
However the most appropriate would be <em>Constitutional Republic</em>.
Explanation:
Federation - a group of states with a central government but independence in internal affairs
Liberal Democracy - representative form of government that does not stick too closely by traditional values, rather ideas of liberalism or new opinions.
Presidential System - a government where there is a head of a so called "executive branch" and is separate from other governing bodies in the nation such as the legislative or judicial body.
Federal Republic - a republic in which states are granted certain governing powers that cannot be revoked by a higher or national governing body.
Constitutional Republic - a government where all political leaders are elected by the public in some way (whether indirect or direct) and all rules are written in a constitution.