Introduction

Constitutional adjudication is much older and more deeply entrenched in the United States than in Europe. Moreover, constitutional adjudication is concrete and a posteriori in the United States, whereas it is, to a large extent, abstract and, in certain cases, ex ante in Europe, suggesting that the former should be inherently less political than the latter. Indeed, in abstract, ex ante review, the constitutional adjudicator tackles laws as they are produced by parliaments, prior to their coming into effect. This gives some European constitutional adjudicators an important policy-making function. Typically, the losing parliamentary minority can challenge the constitutionality of a law it had opposed in the legislature before a constitutional adjudicator who is empowered to strike down the challenged law prior to its actual promulgation, or to condition its promulgation on the adoption of interpretive glosses that limit, alter or expand it. In the United States, on the other hand, judicial review is supposed to be fact driven, meaning that courts are not supposed to decide on the constitutionality of a law in the abstract but only as it applies to particular facts linked to an actual controversy among real adversaries. Two important consequences follow from the American approach: first, constitutional review cannot be triggered in the absence of a concrete controversy; and, second, the factual setting of the relevant controversy tends to anchor constitutional review within a framework that is more conducive to adjudication than to legislation.