The previous constitution, called the Articles of Confederation, gave state governments more authority. Led by Patrick Henry of Virginia, Anti-Federalists worried, among other things, that the position of president, then a novelty, might evolve into a monarchy
Because they traded a lot
Generally speaking, according to nationalists, a nation-state's government should be "strong" and powerful when it comes to establishing things like borders and domestic rule.
Constitutional law is a body of law which defines the role, powers, and structure of different entities within a state, namely, the executive, the parliament or legislature, and the judiciary; as well as the basic rights of citizens and, in federal countries such as the United States and Canada, the relationship between the central government and state, provincial, or territorial governments.