It is hard to think of an issue more clearly reserved to state law under constitutional tradition than the definition of marriage.

WSJ: Michael McConnell: The Constitution and Same-Sex Marriage

Some Eurocrats suggest that the philosophical gap reflects the American constitutional tradition that everything is allowed unless it is forbidden, against the Napoleonic tradition codifying what the state allows and banning everything else.

ECONOMIST: Charlemagne

By tradition, though not by explicit constitutional diktat, foreign policy is the French president's preserve.

ECONOMIST: France

The experience of the British courts, being the fountainhead of the common-law tradition, shows that they have adapted well to the new constitutional paradigm.

CNN: A NEW CONSTITUTIONAL ORDER