The significance of the Constitution in federal governance lies in its role as the supreme law of the land, establishing the framework for the U.S. government. It delineates the powers of various branches, ensuring a system of checks and balances to prevent abuses of power. The Constitution also enshrines fundamental rights and liberties, guiding legislative and judicial actions. It fosters national unity while allowing for state-level autonomy, thus balancing federalism and local governance. Over time, it has adapted through amendments, reflecting evolving social values and norms.