A republic is a form of government in which political power and authority is derived from the citizenry, and not from a monarch, whether hereditary or "tyrannical" (ie, a dictator). In modern use, the term usually refers to a representative democracy, which is further limited by the rule of law.
In a March, 2009 essay reviewing the Federalist Papers published in the New York Review of Books, Cass Sunstein coined the term "enlarged republic" to describe the large-scale, continent-wide republican democracy and federal government of the United States. He contrasted it with previous "small republics" in Athens, Rome, and the Italian city states such as Florence, in all of which republicanism eventually failed. Montesquieu had argued such small republics were the canonical form of republican government and the Federalist Papers were part of the debate over whether an enlarged republic could succeed in North America. "In emphasizing the value of small communities, the antifederalists drew on familiar republican theory."  In the U.S., Sunstein argued, antifederalists including Patrick Henry, Thomas Paine, George Mason and others emphasized the primacy of civic virtue in republics. "Only in small communities would it be possible to check a potentially oppressive government, and to find and develop the unselfishness and devotion to the public good on which genuine freedom depends." 
Antifederalist arguments were posed in opposition to the proposed U.S. Constitution, suggesting that expanding the powers of the federal government was inimical to the development of liberty and would inevitably fail. The authors of the Federalist Papers (generally thought to be a team recruited by Alexander Hamilton, who also included James Madison and John Jay in the project) laid out a series of complex and detailed arguments which made the case for an enlarged republic.
- See also: Republicanism
- Cass Sunstein. "The Enlarged Republic - Then and Now." The New York Review of Books. March 26, 2009. p. 45-47.
- Sunstein, ibid. p. 46
- Sunstein. ibid. p. 46