At Excess of Democracy, Derek Muller flags an interesting case:
An Arizona initiative several years ago took away the power to redistrict from the legislature and put it in the hands of an independent redistricting commission. The legislature is now challenging that this initiative as running afoul of the Times, Places and Manner Clause, which provides that the “manner of holding Elections for Senators and Representatives, shall be prescribed in each state by the legislature thereof.” (A relevant news story here.) The Arizona legislature’s argument is that such power, seized from the legislature by initiative, is prohibited.
As he notes, there have been a number of court cases and scholarly works that bear on the question, but just as an textual matter I have a hard time seeing how "Legislature" in Article I, Section 4, means anything other than, well, the legislature. Among other things, the nearly-adjacent Article I, Section 2, plainly uses the phrase "State Legislature" to mean the elected members of the state's lawmaking assembly, not more broadly any entity person or group with lawmaking authority under state law: "… the Electors [for members of the federal House of Representatives] in each State shall have the Qualifications requisite for Electors of the most numerous Branch of the State Legislature."
Of course, it also seems likely that the framers of Article I, Section 4, meant the state "Legislature" as opposed to the state's executive or judicial branch and didn't have any particular intent with respect to popular initiatives. That makes the case something of a test of how much of a textualist you are.
Posted at 6:38 AM