Why could the constitution be called an illegal document under the rules of article of confederation?

The Constitution could be considered an illegal document under the Articles of Confederation because it was drafted and ratified without the unanimous consent of the states as required by the Articles. The Articles stipulated that any amendments required the agreement of all thirteen states, yet the Constitution was adopted by only nine states. Additionally, the Constitutional Convention operated outside its mandate to merely amend the Articles, effectively overstepping its authority. This perceived illegitimacy fueled debates about the Constitution's validity at the time.