on. The Senate prudently had directed the investigating
committee to ascertain what, if any, other or additional legislation may
be advisable. Conceding "that Congress is without authority to compel
disclosures for the purpose of aiding the prosecution of pending suits,"
the Court declared that the authority "to require pertinent disclosures
in aid of its own constitutional power is not abridged because the
information sought to be elicited may also be of use in such
suits."[104]

JUDICIAL FUNCTIONS

When either House exercises a judicial function, as in judging of
elections or determining whether a member should be expelled, it is
clearly entitled to compel the attendance of witnesses to disclose the
facts upon which its action must be based. Thus the Court held that
since a House had a right to expel a member for any offense which it
deemed incompatible with his trust and duty as a member, it was entitled
to investigate such conduct and to summon private individuals to give
testimony concerning it.[105] The decision in Barry _v._ United States
ex rel. Cunningham[106] sanctioned the exercise of a similar power in
investigating a Senatorial election.

SANCTIONS OF THE INVESTIGATORY POWER

Contempt

Explicit judicial recognition of the right of either House of Congress
to commit for contempt a witness who ignores its summons or refuses to
answer its inquiries dates from McGrain _v._ Daugherty. But the
principle there applied had its roots in an early case, Anderson _v._
Dunn,[107] which affirmed in broad terms the right of either branch of
the legislature to attach and punish a person other than a member for
contempt of its authority--in that case an attempt to bribe one of its
members. The right to punish a contumacious witness was conceded in
Marshall _v._ Gordon,[108] although the Court there held that the
implied power to deal with contempt did not extend to the arrest of a
person who published matter defamatory of the House. Both Anderson _v._
Dunn and Marshall _v._ Gordon emphasized that the power to punish for
contempt rests upon the right of self-preservation; that is, in the
words of Chief Justice White, "the right to prevent acts which in and of
themselves inherently obstruct or prevent the discharge of legislative
duty or the refusal to do that which there is inherent legislative power
to compel in order that legislative functions may be performed."[109]
Whence it was argued, in Jurney _v._ MacCrac