ation of federal employees by adducing proof of
actual bias.

The Constitution does not require Congress to allow peremptory
challenge to jurors in criminal cases. Consequently the contention that
several defendants being tried together on a charge of conspiracy were
denied a trial by an impartial jury because each was not allowed the
full statutory number of peremptory challenges was without merit.[29] It
is good ground for challenge for cause that a juror has formed an
opinion as to the issue to be tried. But every opinion which a juror may
entertain does not necessarily disqualify him. Upon the trial of the
issue of fact raised by such a challenge, the Court must determine
whether the nature and strength of the opinion are such as in law
necessary to raise the presumption of partiality.[30] A member of the
Socialist party is not denied any constitutional right by being tried by
a jury composed exclusively of members of other parties and of property
owners.[31]

Place of Trial

An accused cannot be tried in one district under an indictment showing
that the offense was committed in another;[32] the locality in which the
offense is charged to have been committed determines the place and court
of trial.[33] In a prosecution for conspiracy, the accused may be tried
in any State and district where an overt act was performed.[34] Where a
United States Senator was indicted for agreeing to receive compensation
for services to be rendered in a proceeding before a government
department, and it appeared that a tentative arrangement for such
services was made in Illinois and confirmed in St. Louis, the defendant
was properly tried in St. Louis, although he was not physically present
in Missouri when notice of ratification was dispatched.[35] The offense
of obtaining transportation of property in interstate commerce at less
than the carrier's published rates,[36] or the sending of excluded
matter through the mails,[37] may be made triable in any district
through which the forbidden transportation is conducted. By virtue of a
presumption that a letter is delivered in the district to which it is
addressed, the offense of scheming to defraud a corporation by mail was
held to have been committed in that district although the letter was
posted elsewhere.[38] The Constitution does not require any preliminary
hearing before issuance of a warrant for removal of an accused to the
court having jurisdiction of the charge.[39] The assign