Final answer:
James Madison focused on constitutional law and political theory, proposing a strong federal government as opposed to revising the Articles of Confederation. His preparation for the Constitutional Convention included writing a critical tract on the existing government's flaws.
Step-by-step explanation:
James Madison researched and prepared extensively on the shortcomings of the Articles of Confederation and the needs of a strong federal government prior to the Grand Convention. Before the Constitutional Convention of 1787, Madison authored Vices of the Political System of the United States, a document that criticized the existing government under the Articles and proposed significant changes to the political system, including the establishment of a bi-cameral legislature, separate judicial branch, an executive distinct from the other branches, and the central government's right to tax and to veto state laws 'in all cases whatsoever.' This intense preparation and his pre-Convention ideas signaled Madison's strong advocacy for a new, robust federal Constitution rather than mere amendments to the existing Articles.
Therefore, James Madison researched constitutional law and political theory, making it clear through his writings that he sought to address the systemic problems evident under the Articles of Confederation. His contributions were instrumental in shaping the U.S. Constitution, influenced by the ideas of Enlightenment writers like John Locke and the Baron de Montesquieu. Madison's work underscores the importance of creating a balance between centralized government and the autonomy of individual states.