Taking the Party out of Politics
The Separation of Powers and the Conflicting Pressures on MPs
Too much power in one set of hands risks that all that power might run away with itself, rather than being used for the general good. The “Separation of powers" protects political liberty by dividing government powers.
The legislative is Parliament
The executive is the Government, and the Civil Service
However, the Government is also a subset of the Parliament.
Problem 1: A log jam
If the executive is from party, and the legislative is dominated by another (e.g. in the UK) everything the President (executive) tries to do can be blocked by Congress (legislative)
Problem 2: Too much unrestrained power
The government and ministers are able to push through new laws and plans without proper reflection and consultation, because their own party in Parliament doesn't want to cause too many waves.
Problem 3: Conflict of Interest for MPs
An MP is expected to scrutinize what Government does. BUT: the only way to get promoted is to follow the 'party line'.
How much meaningful scrutiny of their own party do you think that MPs really do?