Document ID: ./input/supremecourt_opinions/opinions/18pdf/18-422_9ol1.pdf
Page Number: 33.0

28 

RUCHO v. COMMON CAUSE 

Opinion of the Court 

is  easy  to  imagine  how  different  criteria  could  move  the 
median map toward different partisan distributions.  As a 
result,  the  same  map  could  be  constitutional  or  not  de-
pending solely on what the mapmakers said they set out to
do.  That possibility illustrates that the dissent’s proposed 
constitutional test is indeterminate and arbitrary.

Even  if  we  were  to  accept  the  dissent’s  proposed  base-
line,  it  would  return  us  to  “the  original  unanswerable 
question  (How  much  political  motivation  and  effect  is  too
much?).”  Vieth, 541 U. S., at 296–297 (plurality opinion).
Would  twenty  percent  away  from  the  median  map  be
okay?  Forty  percent?    Sixty  percent?    Why  or  why  not?
(We appreciate that the dissent finds all the unanswerable 
questions  annoying,  see  post,  at  22,  but  it  seems  a  useful 
way to make the point.)  The dissent’s answer says it all:
“This much is too much.”  Post, at 25–26.  That is not even 
trying to articulate a standard or rule. 

The dissent argues that there are other instances in law 
where matters of degree are left to the courts.  See post, at 
27.  True  enough.  But  those  instances  typically  involve
constitutional  or  statutory  provisions  or  common  law 
confining  and  guiding  the  exercise  of  judicial  discretion.
For example, the dissent cites the need to determine “sub-
stantial  anticompetitive  effect[s]”  in  antitrust  law.    Post, 
at  27  (citing  Ohio  v.  American  Express  Co.,  585  U. S.  ___ 
(2018)).  That language, however, grew out of the Sherman
Act,  understood  from  the  beginning  to  have  its  “origin  in 
the  common  law”  and  to  be  “familiar  in  the  law  of  this 
country  prior  to  and  at  the  time  of  the  adoption  of  the
[A]ct.”  Standard  Oil  Co.  of  N. J.  v.  United  States,  221 
U. S. 1, 51 (1911).  Judges began with a significant body of 
In  other 
law  about  what  constituted  a  legal  violation. 
cases,  the  pertinent  statutory  terms  draw  meaning  from
related provisions or statutory context.  Here, on the other 
hand,  the  Constitution  provides  no  basis  whatever  to 
guide  the  exercise  of  judicial  discretion.    Common  experi-