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Page Number: 59.0

20 

RUCHO v. COMMON CAUSE 

KAGAN, J., dissenting 

276.  A  second  expert  obtained  essentially  the  same  re-
sults  with  maps  conforming  to  more  generic  districting 
criteria  (e.g.,  compactness  and  contiguity  of  districts).
Over  99%  of  that  expert’s  24,518  simulations  would  have 
led to the election of at least one more Democrat, and over 
70% would have led to two or three more.  See Rucho, 318 
F. Supp.  3d,  at  893–894.    Based  on  those  and  other  find-
ings,  the  District  Court  determined  that  the  North  Caro-
lina plan substantially dilutes the plaintiffs’ votes.4 

Because  the  Maryland  gerrymander  involved  just  one
district, the evidence in that case was far simpler—but no
less powerful for that.  You’ve heard some of the numbers 
before.  See supra, at 6.  The 2010 census required only a 
minimal  change  in  the  Sixth  District’s  population—the
subtraction  of  about  10,000  residents  from  more  than 
700,000.  But  instead  of  making  a  correspondingly  mini-
mal  adjustment,  Democratic  officials  reconfigured  the 
entire  district.  They  moved  360,000  residents  out  and 
another  350,000  in,  while  splitting  some  counties  for  the
first  time  in  almost  two  centuries.    The  upshot  was  a
district  with  66,000  fewer  Republican  voters  and  24,000
more Democratic ones.  In the old Sixth, 47% of registered 
voters were Republicans and only 36% Democrats.  But in 
the  new  Sixth,  44%  of  registered  voters  were  Democrats
and only 33% Republicans.  That reversal of the district’s 
partisan  composition  translated  into  four  consecutive
Democratic victories, including in a wave election year for 
—————— 

4 The District Court also relied on actual election results (under both 
the  new  plan  and  the  similar  one  preceding  it)  and  on  mathematical 
measurements of the new plan’s “partisan asymmetry.”  See Rucho, 318 
F. Supp. 3d, at 884–895.  Those calculations assess whether supporters 
of  the  two  parties  can  translate  their  votes  into  representation  with 
equal ease.  See Stephanopoulos & McGhee, The Measure of a Metric, 
70 Stan. L. Rev. 1503, 1505–1507 (2018).  The court found that the new 
North Carolina plan led to extreme asymmetry, compared both to plans
used  in  the  rest  of  the  country  and  to  plans  previously  used  in  the 
State.  See Rucho, 318 F. Supp. 3d, at 886–887, 892–893.