Federalist believed a Bill of Rights was unnecessary, believed the elastic clause was necessary, and wanted a unified government instead of many independent states.
Anti Federalists believed a Bill of Rights was necessary, opposed the elastic clause, they believed that the states should remain independent, and that the Articles of Confederation only needed to be amended.
This is William. William is a federalist.
He is a federalist because, while he supports the idea of a Bill of Rights, he believes the government should be stronger, states should be unified, and that the Articles of Confederation need to be replaced completely.