Answer:
Republicanism is a political ideology which believe that a country should be run by dividing it into smaller states and putting a representative to independently run the affairs on each states.
In Republicanism, the smaller states have high authority to run itself and the central government play very little influence in influencing the outcome of their policies.
Strong Central government will shatter this system because it will put the central government in a position to control the smaller states and force them to conform to a certain policy.
This is why many people believe that a strong central government is a departure from republicanism.