Document ID: ./input/supremecourt_opinions/opinions/19pdf/19-715_febh.pdf
Page Number: 16

Cite as:  591 U. S. ____ (2020) 

11 

Opinion of the Court 

deeply partisan controversy; and that Congress and the Ex-
ecutive have nonetheless managed for over two centuries to
resolve such disputes among themselves without the bene-
fit of guidance from us.  Such longstanding practice “ ‘is a 
consideration of great weight’ ” in cases concerning “the al-
location of power between [the] two elected branches of Gov-
ernment,” and it imposes on us a duty of care to ensure that
we  not  needlessly  disturb  “the  compromises  and  working 
arrangements  that  [those]  branches  . . .  themselves  have 
reached.”  NLRB v. Noel Canning, 573 U. S. 513, 524–526 
(2014)  (quoting  The  Pocket  Veto  Case,  279  U. S.  655,  689 
(1929)).  With  that  in  mind,  we  turn  to  the  question
presented. 

B 
Congress has no enumerated constitutional power to con-
duct  investigations  or  issue  subpoenas,  but  we  have  held
that each House has power “to secure needed information”
in order to legislate.  McGrain v. Daugherty, 273 U. S. 135, 
161 (1927).  This “power of inquiry—with process to enforce 
it—is an essential and appropriate auxiliary to the legisla-
tive function.”  Id., at 174.  Without information, Congress
would be shooting in the dark, unable to legislate “wisely or 
effectively.”  Id., at 175.  The congressional power to obtain 
information  is  “broad”  and  “indispensable.”  Watkins  v. 
United  States,  354  U. S.  178,  187,  215  (1957).    It  encom-
passes  inquiries  into  the  administration  of  existing  laws,
studies of proposed laws, and “surveys of defects in our so-
cial, economic or political system for the purpose of enabling 
the Congress to remedy them.”  Id., at 187. 

Because this power is “justified solely as an adjunct to the
legislative process,” it is subject to several limitations.  Id., 
at 197.  Most importantly, a congressional subpoena is valid 
only if it is “related to, and in furtherance of, a legitimate 
task of the Congress.”  Id., at 187.  The subpoena must serve
a  “valid  legislative  purpose,”  Quinn  v.  United  States,  349