That’s the question raised by a lawsuit in Colorado’s federal district court, in the case of Kerr v. Hickenlooper. In an amicus brief, I suggest that the answer is “no.” The brief relies heavily on the scholarship of my Independence Institute colleague Rob Natelson, who happens to be the leading scholarly expert on the Guarantee clause.
In short, the Founders defined a “republic” to include governments such as those of ancient Athens, Carthage, and Sparta, all of which included elements of direct democracy. According to Minor v. Happersett (U.S. 1875), the decision of Congress to admit a state to the Union is conclusive proof that, at the time, the state had a Republican Form of Government. Massachusetts and Rhode Island had referenda when they were admitted. The progressive movement for initiative and referendum began in the last 19th century. Congress chose to admit Oklahoma (1907) which had very strong I&R provisions in its state constitution, and New Mexico (1911), whose statehood constitution specifically provided for the creation of a citizen initiative system.
Courts have held that the Republican Form of Government issue is not justiciable, and enforcement is up to Congress. The amicus brief, however, addresses the merits of the issue.