s subordinated to what Justice Cardozo called "a benign
and prudent comity."[549] Four years later, and without further
preparation other than a change in two of the Justices, the Court
overturned Swift _v._ Tyson and its judicial progeny in Erie Railroad
Co. _v._ Tompkins,[550] in an opinion by Justice Brandeis which is
remarkable in a number of ways. In the first place, it reversed a
ninety-six year old precedent which counsel had not questioned;
secondly, for the first and only time in American constitutional
history, it held action of the Supreme Court itself to have been
unconstitutional, to wit, action taken by it in reliance on its
interpretation of the 34th section of the Judiciary Act of 1789, a
question which also was not before the Court; and thirdly, it completely
ignored the power of Congress under the commerce clause, as well as its
power to prescribe rules of decision for the federal courts in the
cases enumerated in article III.

Like the Fairmont Coal and Taxicab cases, the Tompkins Case presented
the possibility of a head-on conflict between State and federal rules of
decision. Tompkins was seriously injured by a passing freight train
while he was walking along the railroad's right of way in Pennsylvania.
As a citizen of Pennsylvania, Tompkins could have sued in that State,
but he could also have sued in the federal district court in
Pennsylvania, or in New York because the railroad was incorporated in
the latter State. He elected to sue in the federal court for the
southern district of New York, where he obtained a verdict for $30,000
after the trial judge had ruled that the applicable law did not preclude
recovery. The circuit court of appeals affirmed the judgment because it
thought it unnecessary to consider whether the law of Pennsylvania
precluded recovery, inasmuch as the question was one of general law to
be decided by the federal courts in the exercise of their independent
judgment. Citing Warren's discovery that Swift _v._ Tyson was an
erroneous interpretation of the Judiciary Act of 1789, criticism of the
Tyson doctrine both on and off the bench, and the political and social
defects of the rule in working discriminations against citizens of a
State in favor of noncitizens and in producing injustice and confusion,
Justice Brandeis declared: "If only a question of statutory construction
were involved, we should not be prepared to abandon a doctrine so widely
* * * [followed for] nearly a centu