This Article will examine the history, text, and application of the Guarantee Clause (or Republican Form of Government Clause). It will first examine the historical context in which the Framers enacted Article IV, Section 4. It will then discuss the text and public understanding of the Clause. Then, it will survey the case law at the federal and state level that examines direct democracy—the initiative and referendum—in light of these principles. It will conclude with a summary of modern objections to direct democracy and new challenges to initiatives that intrude on legislative power in the area of civil rights and public finance.