Article IV. STATES' RELATIONSInterestingly, this clause appears to prohibit states from adopting a democracy. In the early days of our Republic, initiative and referendum processes were highly criticized. Easy initiative and referendum processes, such as California's, arguably contravene this section.
§ 4. Obligations of United States to States
The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.
The Washington State Supreme Court discussed the issue in 2006 in State v. Davis, 133 Wn.2d 187, 190-192943 P.2d 283 (Wash., 1997) challenging a "three strikes" law adopted by initiative petition:
"Justiciability" refers to a doctrine by which the courts may dodge an issue saying that it is really a political issue, not a legal issue, and therefore it is not justiciable.
No court in this or any other jurisdiction has invalidated any law on the ground that [943 P.2d 286] its passage by initiative violated the Guarantee Clause. In order to reach that conclusion, the court would have to hold both that the issue is justiciable and that either the initiative process itself or the use of that process to adopt certain kinds of laws is inconsistent with the constitutional notion of a "republican form of government."
In a case challenging the initiative process itself as anti-republican, the Supreme Court long ago held that "the issues presented, in their very essence, are, and have long since by this court been, definitely determined to be political and governmental ... and not therefore within the reach of judicial power ..." Pacific States Tel. & Tel. Co. v. Oregon, 223 U.S. 118, 151, 32 S.Ct. 224, 231, 56 L.Ed. 377 (1912). Since that time, the Supreme Court has suggested that "perhaps not all claims under the Guarantee Clause present nonjusticiable political questions" but has still declined to construe the Guarantee Clause on the ground that the issue is "nonjusticiable under the 'political question' doctrine." New York v. United States, 505 U.S. 144, 184-85, 112 S.Ct. 2408, 2432-33, 120 L.Ed.2d 120 (1992); State v. Owen, 97 Wash. 466, 469, 166 P. 793 (1917); Reynolds v. Sims, 377 U.S. 533, 582, 84 S.Ct. 1362, 1392, 12 L.Ed.2d 506 (1964) ("some questions raised under the Guaranty Clause are not justiciable"). Most precedent from other states is in accord. See California Gillnetters Ass'n v. Department of Fish & Game, 39 Cal.App.4th 1145, 46 Cal.Rptr.2d 338 (1995) (claim that initiative process violated right to republican form of government held not justiciable); New Progressive Party v. Hernandez Colon, 779 F.Supp. 646 (D.Puerto Rico 1991) (claim that referendum process violates guarantee clause held not justiciable); Iman v. Southern Pac. Co., 7 Ariz.App. 16, 435 P.2d 851 (1968) (whether state no longer has republican form of government because of adoption of initiative and referendum procedures held not to be justiciable).
Those courts which have treated the issue as justiciable have uniformly rejected the contention that use of the initiative process is inconsistent with the "republican form of government" guaranteed by U.S. Const. art. IV, § 4. Thus, the Oregon Supreme Court in State v. Montez, 309 Or. 564, 789 P.2d 1352 (1990), rejected a Guarantee Clause challenge to that state's death penalty initiative after finding the issue to be justiciable. 2 The Oklahoma Supreme Court has likewise held that enacting laws through initiatives and referenda does not abolish or destroy the republican form of government. In re Initiative Petition No. 348, 820 P.2d 772 (Okla.1991). And the Colorado Supreme Court has stated that "[l]ike the right to vote, the power of initiative is a fundamental right at the very core of our republican form of government." McKee v. City of Louisville, 200 Colo. 525, 616 P.2d 969, 972 (1980).