oning jurors,[1581] making separate
trials for persons jointly indicted a matter of discretion for the trial
court rather than a matter of right,[1582] and allowing a comparison of
handwriting experts[1583] have been sustained over the objection that
they were _ex post facto_. The contrary conclusion was reached with
respect to the application to felonies committed before a Territory was
admitted to the Union, of the provision in the State constitution which
permitted the trial of criminal cases by a jury of eight persons,
instead of the common law jury of twelve which was guaranteed by the
Sixth Amendment during the period of territorial government.[1584]

OBLIGATION OF CONTRACTS

Definition of Terms

"Law."--The term comprises statutes, constitutional
provisions,[1585] municipal ordinances,[1586] and administrative
regulations having the force and operation of statutes.[1587] How is it
as to judicial decisions? Not only does the abstract principle of the
separation of powers forbid the idea that the courts "make" law, but the
word "pass" in the above clause seems to confine it to the formal and
acknowledged methods of exercise of the law-making function.
Accordingly, the Court has frequently said that the clause does not
cover judicial decisions, however erroneous, or whatever their effect on
existing contract rights.[1588] Nevertheless, there are important
exceptions to this rule which are hereinafter set forth.

Status of Judicial Decisions.--Also, while the highest State
court usually has final authority in determining the construction as
well as the validity of contracts entered into under the laws of the
State, and the national courts will be bound by their decision of such
matters, nevertheless, for reasons which are fairly obvious, this rule
does not hold when the contract is one whose obligation is alleged to
have been impaired by State law.[1589] Otherwise, the challenged State
authority could be vindicated through the simple device of a
modification or outright nullification by the State court of the
contract rights in issue. Likewise, the highest State court usually has
final authority in construing State statutes and determining their
validity in relation to the State constitution. But this rule too has
had to bend to some extent to the Supreme Court's interpretation of the
obligation of contracts clause.[1590]

Suppose the following situation: (1) a municipality, acting under
authority conferred