Document ID: ./input/supremecourt_opinions/opinions/18pdf/18-422_9ol1.pdf
Page Number: 66.0

Cite as:  588 U. S. ____ (2019) 

27 

KAGAN, J., dissenting 

Nor  is  there  any  reason  to  doubt,  as  the  majority  does,
the  competence  of  courts  to  determine  whether  a  district
map  “substantially”  dilutes  the  votes  of  a  rival  party’s
supporters  from  the  everything-but-partisanship  baseline 
described  above.  (Most  of  the  majority’s  difficulties  here 
really  come  from  its  idea  that  ideal  visions  set  the  base-
line.  But that is double-counting—and, as already shown,
wrong  to  boot.)    As  this  Court  recently  noted,  “the  law  is
full  of  instances”  where  a  judge’s  decision  rests  on  “esti-
mating  rightly  . . .  some  matter  of  degree”—including  the 
“substantial[ity]”  of  risk  or  harm.    Johnson  v.  United 
States,  576  U. S.  ___,  ___  (2015)  (slip  op.,  at  12)  (internal 
quotation  marks  omitted);  see,  e.g.,  Ohio  v.  American 
Express  Co.,  585  U. S.  ___,  ___  (2018)  (slip  op.,  at  9)  (de-
termining  “substantial  anticompetitive  effect[s]”  when
applying  the  Sherman  Act);  United  States  v.  Davis,  ante, 
at 7–10 (KAVANAUGH, J., dissenting) (cataloging countless 
statutes  requiring  a  “substantial”  risk  of  harm).  The 
majority  is  wrong  to  think  that  these  laws  typically  (let
alone  uniformly)  further  “confine[ ]  and  guide[ ]”  judicial
decisionmaking.  Ante, at 28.  They do not, either in them-
selves or through “statutory context.”  Ibid.  To the extent 
additional  guidance  has  developed  over  the  years  (as
under the  Sherman Act), courts themselves have been its 
author—as they could be in this context too.  And contrary 
to  the  majority’s  suggestion,  see  ibid.,  courts  all  the  time 
make judgments about the substantiality of harm without 
reducing them to particular percentages.  If courts are no 
longer  competent  to  do  so,  they  will  have  to  relinquish, 
well, substantial portions of their docket.

And  the  combined  inquiry  used  in  these  cases  set  the
bar high, so that courts could intervene in the worst parti-
san  gerrymanders,  but  no  others.   Or  to  say  the  same
thing,  so  that  courts  could  intervene  in  the  kind  of  ex-
treme gerrymanders that nearly every Justice for decades 
has thought to violate the Constitution.  See supra, at 13.