Rucho v. Common Cause, 139 S. Ct. 2484 (2019)

• Result: Ruling that partisan gerrymandering is a non-justiciable political question.
• ISL theory proponents:  contend that in direct contradiction to the theory, all nine Justices agreed that state constitutions can be used as checks against partisan gerrymandering in congressional elections. The Rucho Court’s analysis was informed by the view that the legislative process was bound by the state constitution, as well as state statutes. 

Arizona State Legislature v. Arizona Independent Redistricting Commission (AIRC), 576 U.S. 787 (2015)

• Result: Upholding the use of independent redistricting commissions for federal congressional elections. The Court, in effect, held that “Legislature” in Article I meant that Arizona residents—pursuant to their state constitution—could implement congressional redistricting through an independent commission created by a popular ballot initiative.
• Reasoning: The Court concluded that precedent, such as Smiley v. Holm, 285 U.S. 355 (1932) (see below) “teaches that redistricting is a legislative function, to be performed in accordance with the State’s prescriptions for lawmaking, which may include the referendum and the Governor’s veto.”
• Notable Dissent: Chief Justice Roberts dissented, arguing that provision violated the federal Elections Clause because it was not enacted by the legislature and divested the legislature of the authority to draw congressional districts. AIRC at 842 (Roberts, C.J., dissenting) (“The majority’s contrary understanding requires it to accept a definition of ‘the Legislature’ that contradicts the term’s plain meaning . . . .”).
• ISL theory proponents: Contend that the Court’s 5-to-4 decision was premised on erroneous understanding of the ISL theory’s history.
• ISL theory opponents: Contend that the AIRC Court rejected one version of the ISL theory—that state legislatures have plenary and exclusive power, at least among state entities, to regulate federal elections—by upholding a state constitutional provision that was enacted by popular initiative and created an independent redistricting commission.

Smiley v. Holm, 285 U.S. 355 (1932)

• Result: Unanimously reversing the Minnesota Supreme Court’s ruling that the Elections Clause denied the governor the power to veto election-related statutes passed by the legislature.  The Court held that the Elections Clause does not empower state legislatures to avoid compliance with the legislative procedures set forth in state constitutions.
• Reasoning: The Court explained that the word “legislature” describes not a legislative body, but legislative function that varies by its context.  Holm at 365 (“The Legislature may act as an electoral body, as in the choice of United States Senators under article 1, [section] 3, prior to the adoption of the Seventeenth Amendment.  It may act as a ratifying body, as in the case of proposed amendments to the Constitution under article 5. . . . [and i]t may act as a consenting body, as in relation to the acquisition of lands by the United States under article 1, [section] 8.”). Additionally, the Court reasoned that the Elections Clause does not “endow the legislature of the State with power to enact laws in any manner other than that in which the constitution of the State ha[d] provided that laws shall be enacted.”

Davis v. Hildebrant, 241 U.S. 565 (1916)

• Result: Finding non-justiciable (under the political question doctrine) the issue of whether state voters could reject via referendum an election law passed by the state legislature because resolution would require deciding whether referenda were antithetical to a “republican form of government” and therefore violative of the Guarantee Clause. The Davis Court interpreted the term “legislature” more broadly and ultimately held that a referendum authorized by a state constitution “was part of the legislative power of the State.”

McPherson v. Blacker, 146 U.S. 1 (1892)

• Result: Affirming the Michigan Supreme Court’s ruling that the state legislature could, without violating the Electors Clause, delegate the selection of presidential electors to voters by having each of the state’s twelve congressional districts elect their presidential electors.
• ISL theory proponents: Argue that the Court endorsed the ISL theory, and point to the Court’s use of “plenary” to describe the state legislature’s power to regulate the selection of electors. Although primarily in dicta, proponents cont
• ISL theory opponents: Contend that the Court distinguished a state legislature as a political body from a state’s “legislative power”—noting that this power could be both limited by the state’s constitution or “elsewhere reposed” (i.e., vested somewhere other than the legislative body).