What do federal, unitary and confederation systems of government have in common?

Answer Elections
Explanation:    
The unitary, confederation and federal systems of government consider elections as an important aspect of their existence. These systems extend the opportunity to the citizens at different levels of centralisation.

The second , larger puritan colony of massachusetts bay was conceived as a "city upon a hill". but it also struggled with internal turmoil like the salem witch trials and external conflicts like king philip's (metacom's) war.