The advantage to separation of powers is:

History has shown time and time again that, in most situations, unlimited power in the hands of one person or party means that others are suppressed or their powers are curtailed. In a democracy, the division of powers is to avoid the misuse of authority and to protect equality for all.

Explanation:

whose power in the senate is equal to the power of the speaker of the house?

the american civil war was not caused   by slavery but by economic factors.