...the language of the Constitution concerning the division of powers between Brussels and national governments is imprecise. The Constitution enumerates areas where Brussels has "exclusive" competence. But, it also states that "in areas which do not fall within its exclusive competence the Union shall act only if and insofar as the objectives of the intended action cannot be sufficiently achieved by the Member States, either at central level or at regional and local level, but can rather, by reason of the scale or effects of the proposed action, be better achieved at Union level." That sentence suggests that Brussels might exercise some competence outside its exclusive authority if some undefined body decides that the EU could do it better than a member state.

Similar problems arise out of areas where the competences are to be "shared" between Brussels and national governments. Such areas include internal market, security and justice, agriculture and fisheries, transport, energy, social policy, economic, social and territorial cohesion, environment, consumer protection and common safety concerns in public health matters. But the Constitution also states that "the member states shall exercise their competence to the extent that the Union has not exercised, or has decided to cease exercising, its competence." In other words, member states may be allowed to legislate in areas of "shared" competences only when Brussels allows them to do so.

Over time, all governments seek broader powers than first authorized. To quote Madison, "In framing a government, which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed, and in the next place, oblige it to control itself." That is why the U.S. Constitution was crafted in a way that carefully enumerates and thereby limits the powers of the federal government.

"It will be of little avail to the people that the laws are made by men of their own choice if the laws be so voluminous that they cannot be read, or so incoherent that they cannot be understood."