This lecture outlines key modern constitutional law issues, emphasizing the application of established doctrines—like the First and Fourth Amendments, and the Commerce Clause—to contemporary challenges. It examines the intersection of constitutional principles with technology and privacy, campaign finance, commercial speech, executive power, and emerging areas such as environmental regulation and healthcare. The lecture also addresses the evolving role of federalism and the impact of the “major questions” doctrine. Landmark Supreme Court cases are used to illustrate these concepts, providing students with a framework for analyzing hypothetical scenarios. Finally, it emphasizes the need to apply fundamental constitutional principles to twenty-first-century problems.