why do all state constitutions have to be in agreement with the us constitution
State constitution (United States) The Tenth Amendment to the United States Constitution, part of the Bill of Rights, provides that "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." The Guarantee Clause of Article 4 of the Constitution states that "The United States shall guarantee to every State in this Union a Republican Form of Government." These two provisions indicate states did not surrender their wide latitude to adopt a constitution, the fundamental documents of state law, when the U.S. Constitution was adopted.
United States Constitution The United States Constitution is the supreme law of the United States.[1] The Constitution, originally comprising seven articles, delineates the national frame of government. Its first three articles embody the doctrine of the separation of powers, whereby the federal government is divided into three branches: the legislative, consisting of the bicameral Congress; the executive, consisting of the President; and the judicial, consisting of the Supreme Court and other federal courts. Articles Four, Five and Six embody concepts of federalism, describing the rights and responsibilities of state governments and of the states in relationship to the federal government. Article Seven establishes the procedure subsequently used by the thirteen States to ratify it. It is regarded as the oldest written and codified constitution in force of the world.[2]