Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-1271_3f14.pdf
Page Number: 28.0

Cite as:  600 U. S. ____ (2023) 

23 

Opinion of the Court 

drew no distinction between “procedural” and “substantive”
restraints on lawmaking.  It turned on the view that state 
constitutional provisions apply to a legislature’s exercise of 
lawmaking authority under the Elections Clause, with no
concern  about  how  those  provisions  might  be  categorized.
285  U. S.,  at  367–368;  see  also  Hildebrant,  241  U. S.,  at 
569–570. 

The same goes for the Court’s decision in Arizona State 
Legislature.  The defendants attempt to cabin that case by 
arguing that the Court did not address substantive limits 
on the regulation of federal elections.  But as in Smiley, the 
Court’s decision in Arizona State Legislature discussed no 
difference between procedure and substance.

The dissent reads Smiley and Arizona State Legislature 
in a different light.  JUSTICE THOMAS thinks those cases say
nothing about whether a State can impose “substantive lim-
its”  on  the  legislature’s  exercise  of  power  under  the  Elec-
tions  Clause.    Post,  at  21.  But  in  Smiley,  we  addressed 
whether “the conditions which attach to the making of state 
laws” apply to legislatures exercising authority under the 
Elections Clause.  285 U. S., at 365.  We held that they do.
“Much that is urged in argument with regard to the mean-
ing of the term ‘Legislature,’ ” we explained, “is beside the 
point.”  Ibid.  And we concluded in straightforward terms 
that  legislatures  must  abide  by  “restriction[s]  imposed  by
state  constitutions . . . when  exercising  the  lawmaking 
power”  under  the  Elections  Clause.    Id.,  at  369.    Arizona 
State Legislature said much the same, emphasizing that, by 
its text, nothing in the Elections Clause offers state legisla-
tures carte blanche to act “in defiance of provisions of the 
State’s constitution.”  576 U. S., at 818. 

The defendants and JUSTICE THOMAS do not in any event 
offer a defensible line between procedure and substance in 
this context.  “The line between procedural and substantive 
law  is  hazy.”  Erie  R. Co.  v.  Tompkins,  304  U. S.  64,  92 
(1938) (Reed, J., concurring in part); see also Shady Grove