Why did federalist argue for a new charter that would replace the articles of confederation?

To strengthen the central government.

Explanation:

The federalists argued that the Articles of Confederation weakened the Congress of its power and sovereignity. Though Congress was endowed with numerous powers on paper, in reality the Articles rendered no real power to the Congress.

This was seen as a major threat by the federalists so they demanded for a new charter called The Constitution to strengthen the central government/Congress. The federalists finally concluded the Constitutional Convention of 1787 and a the US Constitution was drafted.

its a example of imperialism