Document ID: ./input/supremecourt_opinions/opinions/boundvolumes/558bv.pdf
Page Number: 199.0

38 

PORTER  v.  McCOLLUM 

Per Curiam 

the heinous, atrocious, and cruel aggravating factor.  Id., at 
937  (Anstead,  J.,  concurring  in  part  and  dissenting  in  part). 
Porter  thereafter  ﬁled  his  federal  habeas  petition.  The 
District Court held Porter’s penalty-phase counsel had been 
ineffective.  It  ﬁrst  determined  that  counsel’s  performance 
had  been  deﬁcient  because  “penalty-phase  counsel  did  little, 
if  any  investigation  .  .  .  and  failed  to  effectively  advocate 
on  behalf  of  his  client  before  the  jury.”  Porter  v.  Crosby, 
No.  6:03–cv–1465–Orl–31KRS,  2007  WL  1747316,  *23  (MD 
Fla., June 18, 2007).  It then determined that counsel’s deﬁ­
cient  performance  was  prejudicial,  ﬁnding  that  the  state 
court’s  decision  was  contrary  to  clearly  established  law  in 
part  because  the  state  court  failed  to  consider  the  entirety 
of the evidence when reweighing the evidence in mitigation, 
including  the  trial  evidence  suggesting  that  “this  was  a 
crime  of  passion,  that  [Porter]  was  drinking  heavily  just 
hours  before  the  murders,  or  that  [Porter]  had  a  good  rela­
tionship with his son.”  Id., at *30. 

The Eleventh Circuit reversed.  It held the District Court 
had  failed  to  appropriately  defer  to  the  state  court’s  factual 
ﬁndings with respect to Porter’s alcohol abuse and his men­
tal  health.  552  F.  3d  1260,  1274,  1275  (2008)  (per  curiam). 
The  Court of  Appeals  then  separately considered  each  cate­
gory of mitigating evidence and held it was not unreasonable 
for  the  state  court  to  discount  each  category  as  it  did.  Id., 
at  1274.  Porter  petitioned  for  a  writ  of  certiorari.  We 
grant  the  petition  and  reverse  with  respect  to  the  Court  of 
Appeals’  disposition  of  Porter’s  ineffective-assistance  claim. 

II 

To  prevail  under  Strickland,  Porter  must  show  that  his 
counsel’s  deﬁcient  performance  prejudiced  him.  To  estab­
lish  deﬁciency,  Porter  must  show  his  “counsel’s  representa­
tion  fell  below  an  objective  standard  of  reasonableness.” 
466 U. S., at 688.  To establish prejudice, he “must show that 
there  is  a  reasonable  probability  that,  but  for  counsel’s  un­